01麥金德的世界

 

第一章 麥金德的世界

鋼鐵帶上的帝國夢：西伯利亞鐵路的落成

西伯利亞鐵路是一條連接兩大洲的鋼鐵帶。它近6000英里的鐵軌連接著莫斯科和符拉迪沃斯托克；連接線橫跨歐洲，延伸至亞洲東部邊緣。一個多世紀以來，西伯利亞鐵路吸引著無數渴望穿越世界上一些最偏遠、有時最美麗的地區的旅行者。然而，當西伯利亞鐵路在1904年建成時，它既是帝國夢的象徵，也是地緣政治噩夢的隱喻。

沙皇政府修建這條鐵路的目的在於彰顯自身榮耀，並開發西伯利亞資源。鐵路的倡導者謝爾蓋·維特伯爵認為，這將使俄羅斯取代蘇伊士運河，確保對中國北方的政治控制。但這也引起了競爭對手日本的警覺。一位日本指揮官預言：「西伯利亞鐵路建成之日，便是朝鮮危機爆發之日。」東京絕不會坐視不理，1904年日俄戰爭隨之爆發。

衝突的通道：從世界大戰到現代烏克蘭

這條鐵路在隨後的血腥時代中成為了一個衝突爆發點。它促成了第一次世界大戰的爆發，使德國擔心俄羅斯「蒸汽壓路機」的加速。在第二次世界大戰中，它先是作為軸心國間的物資通道，後成為美國租借物資支援蘇聯的前線紐帶。

到了2022年，這條鐵路再次發揮了陰暗的作用。弗拉基米爾·普丁利用西伯利亞鐵路將大量坦克與部隊從遠東運往烏克蘭邊境，其中包括後來在布查犯下罪行的第64摩托化步兵旅。130多年後，地理環境雖未改變，但技術進步使這條鐵路始終位於衝突的核心。

麥金德：身兼數職的博學家與地緣政治奠基人

哈爾福德·麥金德爵士（1861-1947）的思想預示了未來一個世紀衝突的基本模式。他是一位典型的博學家：曾是牛津大學教授、倫敦政經學院創辦人、國會議員、甚至是首位登頂肯亞山的登山家。

雖然麥金德在政壇未曾登頂，但他作為「地緣政治學」奠基人的影響力遠超許多將軍。他主張，地理深刻地塑造了權力鬥爭。他曾斷言：「是人而非自然開啟了變革，但自然在很大程度上掌控著一切。」這種思維對英國繁榮至關重要，因為世界正處於翻天覆地的變化中。

輝煌孤立的終結：十九世紀末的變局

麥金德成長於英國勢力無所不在的時代，但到了1890年，英國的霸權開始消逝。新興強國如德國、美國和日本正快速崛起，大英帝國處處危機四伏。同時，意識形態的鴻溝也日益擴大，民主的英國與專制的俄國、德國之間展現了價值觀的較量。

此外，世界正變得「擁擠且窒息」。隨著輪船、鐵路和電報的普及，加上殖民擴張的空間飽和，大國之間的關係變成了零和博弈。麥金德意識到，一個「封閉的政治體系」將帶來更劇烈的衝突。

歷史的地理樞紐：歐亞大陸霸權論

1904年，麥金德發表了著名的演講《歷史的地理樞紐》。他指出「哥倫布時代」——歐洲向外擴張的時代——已經結束。現在，科技（尤其是鐵路）正重塑地理，使陸上力量具備了與海上力量競爭的機動性。

他提出「樞紐區域」（中心地帶）的概念，認為一個若能控制歐亞大陸核心區域的強權，將擁有無與倫比的資源，進而打造強大海軍，主宰世界。這引出了他著名的格言：「誰統治了中心地帶，誰就統治了世界島；誰統治了世界島，誰就統治了世界。」

離岸平衡者與馬漢的海權論

在麥金德擔憂舊世界時，新世界的戰略家阿爾弗雷德·塞耶·馬漢則提出了不同的觀點。馬漢認為：「誰統治了海洋，誰就統治了世界。」他主張，海上貿易是國家的命脈，控制海洋意味著能遏制陸上的敵人。

馬漢意識到俄羅斯在亞洲擴張的威脅，因此提出英美應攜手合作，建立前線防禦。馬漢的思想為20世紀的英美聯盟奠定了理論基礎，旨在確保歐亞大陸不被單一專制強權壟斷。

史派克曼與「邊緣地帶」理論

二戰期間，耶魯大學的尼古拉斯·斯皮克曼（Nicholas Spykman）對麥金德的理論進行了修正。他認為真正的威脅不在於荒涼的核心地帶，而在於人口稠密、經濟活躍的「邊緣地帶」（Rimland）。

史派克曼主張：「誰控制了邊緣地帶，誰就統治了歐亞大陸。」他警告，如果軸心國控制了歐亞邊緣地帶，美國將被完全包圍並在經濟上被窒息。這促使美國放棄孤立主義，轉而積極介入歐亞事務以維持權力平衡。

威權主義地緣政治：生存空間與豪斯霍費爾

地緣政治學中也存在陰暗的一面。德國的卡爾·豪斯霍費爾（Karl Haushofer）將麥金德的理論用於擴張目的。他提出「生存空間」（Lebensraum）概念，主張德國必須建立一個涵蓋歐亞的大帝國。

豪斯霍費爾的思想深深影響了希特勒，為納粹的侵略戰爭提供了理論武裝。雖然他後來與納粹產生分歧，但其理論卻玷污了地緣政治學的名聲，使其一度與侵略掛鉤。

現代迴響：杜金與新威權軸心

麥金德的辯論在一個世紀後依然響亮。俄羅斯知識分子亞歷山大·杜金（Aleksandr Dugin）繼承了豪斯霍費爾和麥金德的邏輯，主張建立「歐亞帝國」以對抗美方的「大西洋主義」。

同時，美國五角大廈的戰略家安德魯·馬歇爾也警告，中國的崛起正是在爭奪歐亞大陸的影響力。麥金德揭示的動態——技術進步、空間縮小、以及極權國家的擴張夢想——至今仍是全球衝突的核心邏輯。歐亞世紀的殘酷歷史，正在證明他的預言多麼準確。

第一章 麥金德的世界

西伯利亞鐵路是一條連接兩大洲的鋼鐵帶。它近6000英里的鐵軌連接著莫斯科和符拉迪沃斯托克；連接線橫跨歐洲，延伸至亞洲東部邊緣。一個多世紀以來，西伯利亞鐵路吸引著無數渴望穿越世界上一些最偏遠、有時最美麗的地區的旅行者：烏拉爾山脈、貝加爾湖畔、以及俄羅斯草原令人驚嘆的孤獨。然而，當西伯利亞鐵路在1904年建成時，它既是帝國夢的象徵，也是地緣政治噩夢的隱喻^。

沙皇政府修建這條鐵路──一項耗資龐大、舉債興建的工程──其目的在於彰顯自身榮耀。這條鐵路旨在將資源豐富的西伯利亞地區開發利用，促進其定居和工業化。它將使俄羅斯帝國能夠加強其在滿洲、朝鮮以及整個遠東地區的影響力。鐵路的倡導者謝爾蓋·維特伯爵認為，這條鐵路將促進對外擴張和國內鞏固；它「不僅將打開西伯利亞的大門，還將徹底改變世界貿易，取代蘇伊士運河成為通往中國的主要通道，使俄羅斯能夠向中國市場大量供應紡織品和金屬製品，並確保對中國北方的政治控制。」^²

西伯利亞鐵路改變了世界，但並非如維特所願。作為俄國在該地區的競爭對手，日本對即將發生的一切瞭如指掌。火車可以運兵，因此加強與東北亞的交通聯繫將使沙皇帝國得以在東京的後院佔有一席之地。 「西伯利亞鐵路建成之日，便是朝鮮危機爆發之日，」一位日本指揮官預言道，「而當朝鮮危機爆發時，整個東方都將陷入動盪。」^³ 東京絕不會坐視不理。就在最後一段鐵軌即將完工的幾個月前，日本對旅順港的俄國艦隊發動了突襲，拉開了二十世紀第一場大國戰爭的序幕──一場爭奪東北亞霸權的戰爭。

這預示著未來將發生的事情。西伯利亞鐵路在隨後的血腥時代中成為了一個衝突爆發點。

以西伯利亞鐵路為骨幹的俄羅斯鐵路網現代化，使德國官員相信，笨重的俄羅斯蒸汽壓路機很快就能以現代的速度投入使用，從而促成​​了第一次世界大戰的爆發。德皇威廉二世憂心忡忡地說：「俄羅斯的大型鐵路建設是為一場大戰做準備。」^⁴ 在引發第一次世界大戰的內戰期間，俄羅斯各派為爭奪鐵路而戰；人們擔心布爾什維克——或者德國人——可能會控製鐵路，這促使華盛頓和其他列強進行了一次徒勞的干預。美國國務院官員毫不掩飾這次行動的目標：「維護、運作和控制西伯利亞鐵路」是其「首要且至關重要的步驟」。 ^⁵

同一條鐵路在下一次世界大戰中扮演了關鍵角色。 1939年至1941年間，西伯利亞鐵路是軸心國之間的經濟通道，而當時實際上與德國結盟的蘇聯則充當了中間人。到1941年春季，這條鐵路每天將300噸至關重要的橡膠從日本日益擴張的帝國運往德國。 ^⁶ 1941年6月希特勒與史達林決裂後，這條鐵路幫助鞏固了確保德國戰敗的聯盟。大量美國租借援助物資經由西伯利亞鐵路從海參崴運往史達林的歐洲前線。 ^⁷ 幾十年後，當弗拉基米爾·普丁準備入侵烏克蘭時，這條鐵路為另一場殘酷的決戰埋下了伏筆。

在二戰以來歐洲最大規模衝突緩慢而充滿威脅的醞釀過程中，普丁利用西伯利亞鐵路將軍事力量從歐亞大陸的一端運送到另一端。軍用列車將坦克、卡車、步兵和飛彈發射器從俄羅斯遠東地區運往烏克蘭邊境。參與此次運輸的部隊之一，第64獨立摩托化步兵旅，參與了在基輔郊區布查對平民的強姦、酷刑和謀殺。布查這個名字後來成為了俄羅斯墮落的代名詞。 8 「^有些瘋子以殺人為樂，」該部隊的一名成員承認，「這樣的瘋子就出現在那裡。」^{9 1891 年，沙皇亞歷山大三世曾宣布：「修建鐵路。」 130}多年後，西伯利亞鐵路仍然是衝突的通道。 10

這其中自有緣由。地理環境固然難以改變；除非擴張或收縮，否則一個國家的位置就固定不變。因此，任何改變地理格局或削弱地理限制的發展，都可能深刻地影響世界局勢。蘇伊士運河的開鑿，大幅縮短了宗主國與邊緣地區之間的旅行時間，大大推動了歐洲在亞洲和非洲建立帝國。 19世紀橫貫大陸鐵路的修建，使美國得以掌控北美大陸，進而在20世紀成為全球超級大國。西伯利亞鐵路的建成，使得軍隊能夠迅速橫跨歐亞大陸；它預示著未來將出現技術革命，進而促成更大規模的征服行動。因此，西伯利亞鐵路的完工預示著一個全球衝突時代的到來。

哈爾福德·麥金德爵士在那個時代即將到來之際發表的演講中預見了它的到來。麥金德的思想預示了未來一個世紀衝突的基本模式。這使他捲入了一場跨越國界和數十年的關於現代地緣政治和戰略的宏大辯論。這些思想對那些致力於維護人類自由世界的人，以及那些試圖摧毀這個世界的人，都產生了深遠的影響。歐亞大陸世紀所有最偉大的戰爭和對抗，都是爭奪麥金德世界統治權的鬥爭。

約翰‧梅納德‧凱恩斯曾寫道： 「那些自認為完全不受任何思想影響的務實之人，通常都是某個已故經濟學家的奴隸。那些身居高位、聽聞異事的瘋子，他們的狂熱不過是從幾年前某個學院派作家的著作中提煉而來。」^¹¹凱因斯的意思是，思想先於政策，這一點即使是政策制定。這或許有助於我們理解哈爾福德·麥金德的生平及其遺產。

平心而論，麥金德並非默默無聞的作家。他於1861年出生於英格蘭中部蓋恩斯伯勒，一直活到1947年——這段時期涵蓋了歐洲帝國主義和英國霸權的鼎盛時期、兩次世界大戰的爆發以及非殖民化和冷戰的開端。麥金德小時候讀到俾斯麥的普魯士擊敗法國、統一德國的新聞，不禁思考一個新興帝國在歐洲中心的鞏固將會帶來什麼。這是一個非凡的時代，而麥金德在長達六十年的職業生涯中也成就斐然^。

他具備追求雄心壯志和冒險精神的潛質。麥金德的父親是一位醫生，他先在寄宿學校接受教育，後進入牛津大學深造。他精通語言，掌握了法語和德語，並且對探索充滿熱情，這種熱情將引領他——無論是在身體上還是在精神上——環遊世界。正如他自己所說，麥金德或許“有點孤僻”，酷愛書籍和地圖，但他體格強健、運動能力出色，並且心智成熟。 13 ¹⁹世紀80年代初，在大學裡，他培養了對地質學和歷史的熱情，在牛津辯論社積極參與公共演講和學術辯論，並透過加入牛津陸軍志願後備隊和大學步槍隊為大英帝國效力。畢業後，麥金德最初想成為一名律師，但最終選擇了一條非同尋常的道路。

麥金德最初靠著講授地理課賺取外快，25歲時憑藉一次演講成功將這份副業發展成為牛津大學的教授職位，這次演講也幫助確立了地理學作為一門獨立的學科的地位。他後來在創辦一系列著名學術機構——牛津地理學院、雷丁大學和倫敦政治經濟學院——中發揮了重要作用，並成為一位公共知識分子，著述涵蓋關稅政策、戰爭與和平的根源等諸多領域。之後，麥金德投身政界，於1910年至1922年間擔任格拉斯哥卡姆拉奇選區的下議院議員。第一次世界大戰後，他嘗試涉足政壇，擔任英國駐南俄高級專員，試圖平息戰爭和革命造成的混亂局面。

1922年失去議會席次後，麥金德重返公共服務領域，擔任一些看似不起眼卻至關重要的機構的主席，例如帝國航運委員會。該委員會旨在維繫大英帝國的團結，即便當時離心力正將帝國撕裂。此外，麥金德還是一位技藝精湛的登山家，曾率隊首次成功登頂肯亞山。一位同時代的人指出，那次攀登「堪稱一項真正的登山壯舉」——儘管它也是一次致命的冒險，並被麥金德參與謀殺叛亂的非洲搬運工的傳聞（從未得到證實）所蒙上陰影。 ^¹⁴

麥金德是一位典型的博學家；他身兼數職。 「我並不認為自己是個浪蕩子，因為我通常都知道自己要去哪裡，」他說道，「但我肯定沒有停滯不前。」^¹⁵

He had, alas, known disappointment. Mackinder didn’t accomplish all he intended. His highest aspiration was to be a heavy hitter in British policy—a man of ideas who was also a man of action. “If he got his foot on the ladder he might go far towards the top,” one observer predicted in 1902, “especially as there is an absence of able young men.”¹⁶ Climbing Mount Kenya proved easy by comparison.

Mackinder was not a natural politician, in part because of his abstract intellectual style. He never became a member of the Cabinet or otherwise really broke into the highest levels of the policy elite. His stint as High Commissioner was short and inglorious; his most comprehensive statement on foreign policy, a book titled Democratic Ideals and Reality, was mostly ignored for a generation after it was published. Mackinder, wrote his friend Leo Amery, had a “more forceful personality and a more powerful brain” than his higher-flying colleagues. But he “never quite made the mark once expected by him.”¹⁷

Yet if Mackinder failed to get his hands firmly on the levers of power, he still left a lasting imprint. Mackinder prided himself on his ability to think big—to see beyond the present crisis and grasp the historical forces at work. It was essential, he wrote, that leaders of a democracy “be able easily and happily to roam in thought over the surface of the world, thinking in millions, thinking in ages.”¹⁸ Those who heard him speak on the subjects he knew best never doubted his ability; decades later, one colleague recalled how Mackinder, so “tall, erect, distinguished,” would enrapture his students by delivering, “in his sonorous voice, without ever a note, a perfectly argued and presented synthesis.”¹⁹ Where Mackinder most excelled was in explaining geopolitics, a discipline focused on the relationship between geographical realities and political power.²⁰

In his field-defining lecture, “On the Scope and Methods of Geography,” Mackinder insisted that the discipline involved more than the mere cataloguing of physical facts; such a dry endeavor “must always fail to attract minds of an amplitude fitting them to be rulers of men.”²¹ Mackinder’s version of geography—political geography—involved studying how the earth’s features affected the behavior of peoples and societies across the long arc of history, and how their behavior, in turn, reshaped the physical environment. This required imagination and sweep: “Humdrum detail is the greater part of every science, but no science can satisfy the mind which does not allow of the building of palaces out of its bricks.”²² Few built mental palaces more majestic than Mackinder’s.

One of his most-read books showed how Britain’s geography and geology—the combination of its resource endowments and position off Europe’s coast—had turned a small island nation into a wealthy, liberal sea power with a peerless empire. Another volume explained how the features of the Rhine River Valley had influenced the long contest to rule Central Europe.²³ The vital theme of Mackinder’s work was that geography profoundly shaped the timeless struggle for power: It wasn’t quite destiny, but it was a reality no good strategist could ignore. “Man and not nature initiates,” he asserted, “but nature in large measure controls.”²⁴ Which meant that training its people and leaders in a geographical way of thinking was essential for Britain to thrive, especially as the world began to change in epochal ways.

The world of Mackinder’s upbringing was a world of ubiquitous British power. London was the global hegemon of the nineteenth century; its influence reached into every inhabited continent. The Royal Navy patrolled the seas, allowing commerce to boom and an age of globalization to ignite. Indeed, London presided over what we would now call a liberal international order; the first great international expansion of democracy happened when British-style representative institutions took hold amid British primacy.²⁵ Notwithstanding some nasty but mostly localized wars, Europe was enjoying its long post-Napoleonic peace, allowing London to avoid continental entanglements and bask in “splendid isolation.” The symbolic apex of British splendor was Queen Victoria’s Diamond Jubilee in 1897, which showcased the world’s best warships and imperial troops from around the globe. The atmosphere, recalled historian Arnold Toynbee, was, “Well, here we are on top of the world, and we have arrived at this peak to stay there—forever!”²⁶

In reality, British power—and international stability—were slipping away. Britain had lost one crucial pillar of its hegemony; by 1890, it no longer had the world’s largest economy. A cohort of rising powers—Prussia (later Germany), America, and Japan—were asserting their interests and reordering their regions through short, sharp wars. France and Britain almost came to blows in 1898 over imperial visions that collided in Sudan; by 1899, London was embroiled in an ugly colonial scrap against the Boers in southern Africa. Russia, Britain’s long-standing rival along fault lines from Eastern Europe to South Asia, was building up its economy and military. The British Empire was beset by crises everywhere. As Colonial Secretary Joseph Chamberlain put it, “The weary Titan staggers under the too vast orb of his fate.”²⁷

Geopolitical upheaval went hand in hand with sharpening ideological conflict. Clashes between opposing ideas, between competing systems of government, are as old as history. Such clashes had, however, temporarily subsided after the ideological flames ignited by the French Revolution were finally extinguished. The countries that defeated Napoleon and established the Concert of Europe in 1814–15 had shared a preference for order, which trumped, for a time, their different conceptions of justice.²⁸ As the Concert broke down in the late nineteenth century, ideological tensions flared anew.

The Great Game was not just a rivalry between voracious empires; the stark and widening gap between a democratizing Britain and a despotic Russia made that contest one of values, too. “We are not of the same make,” the British minister in Tehran wrote. “We differ as our governments differ.”²⁹ The leaders of another British rival, Germany, had committed themselves to seeking greatness through autocracy and coercion. Germany’s chancellor, Otto von Bismarck, had once declared that history would be made not “by speeches or majority decisions” but “by blood and iron.” Prussia had become strong, he explained, “not through liberalism and free-thinking” but through the guidance of resolute authoritarians who acted with “ruthless courage.”³⁰ A key question of the twentieth century, Mackinder and many contemporaries believed, was whether liberal states or their illiberal challengers would set the rules of the road.

Even war itself had changed. Gone were the languid, desultory conflicts that Europe’s cash-strapped monarchies had waged in an earlier era. The French Revolution had opened an era of total war—contests in which modern states, driven by fierce nationalism and boasting sophisticated bureaucratic and financial capabilities, harnessed society’s energies to seek the outright destruction of their foes. In the 1860s, the U.S. Civil War had demonstrated how combatants could mobilize manpower, money, and industrial muscle on a scale previously unheard of, to fight wars longer, more destructive, and more consuming than before. Even the smaller, shorter wars that followed—the wars of German unification, the Sino-Japanese war, the Boer War—displayed the devastating effects of modern firepower and mass-produced weapons. As the international system grew more disordered, great-power collisions grew more devastating.³¹

Finally, by the dawn of the twentieth century the world was getting more crowded, claustrophobic. Progress was partly to blame; steamships, railroads, and telegraphs were thrusting people and continents together. Conquest was another culprit. The rapid-fire European imperial aggrandizement of the late nineteenth century, what one foreign minister called a “veritable steeplechase for colonial acquisitions,” had created mega-empires—with Britain’s the largest—that covered the globe. Influenced by social Darwinism and the notion that only the fittest would survive, strategists throughout Europe and beyond insisted that countries must expand, engorging themselves with lands and resources, or be devoured by their rivals. Strong states “assert themselves in the universal economy of nature,” wrote one retired German general. “The weaker succumb.”³² Mackinder’s world was becoming a tinderbox intellectually as well as politically.

The opening decade of the 1900s was a moment of tectonic change in world politics—even if it was, understandably, difficult for contemporary observers to make out just what was happening and why. That was Mackinder’s task when he visited the Royal Geographic Society on the evening of January 25, 1904, to deliver a lecture called “The Geographic Pivot of History.”

Few strategic texts of the modern era were more seminal; Mackinder’s lecture influenced generations of military, diplomatic, and political leaders. Yet you might not have guessed it at the time.

The talk wasn’t an immediate hit; one attendee “looked with regret on some of the space which is unoccupied here.”³³ Perhaps that was because it was a frigid January night. Or perhaps it was because Mackinder’s lecture combined vague abstraction, meandering narration, distant history, and mountains of geographical detail. The talk featured a long, if graceful, discussion of rivers, steppes, peaks, and monsoon lands; it was full of concepts (“Pivot Area,” “Inner Crescent,” “Outer Crescent”) that then probably seemed obscure. Mackinder asked a lot of his listeners. He also delivered a lot, for the analytical heart of his lecture was a penetrating discussion of the forces producing a Eurasian century.

First was the end of what Mackinder termed the “Columbian epoch”—that 400-year age of European exploration and conquest that began with the discovery of the Americas. “Whereas mediaeval Christendom was pent into a narrow region and threatened by external barbarism,” Mackinder explained, the Columbian epoch had seen “the expansion of Europe against almost negligible resistances.”³⁴ The major European states had mapped and divided the globe; the process had accelerated in the nineteenth century as advances in firepower, medicine, and transportation drove imperial penetrations deep into Africa and Asia. Not long after Mackinder spoke, Britain would control an empire of 31 million square kilometers; the French empire, at 12.5 million square kilometers, was twenty times larger than France itself.³⁵ Yet now the Columbian epoch was ending, a victim of catastrophic success.

There were no more worlds to conquer. Africa and much of Asia had been subjugated; the “new Europes” of Australia, Canada, and New Zealand were part of the British Empire. There was “scarcely a region left for the pegging out of a claim of ownership, unless the result of a war between civilized or half-civilized powers,” Mackinder said.³⁶ Britain had gained the most from this orgy of aggrandizement, but the implications were ominous nevertheless.

The European powers had, since Napoleon’s demise, mostly avoided all-out conflict, in part because expansion directed their aggression outward; a “long war” against less developed societies facilitated a “long peace” among the empires themselves.³⁷ Now this safety valve was closed. “Every explosion of social forces, instead of being dissipated in a circuit of unknown space and barbaric chaos, will be sharply re-echoed from the far side of the globe.” A “closed political system” would be vicious; great-power relations were becoming zero-sum.³⁸

Tensions were also rising for a second reason: technology was remaking geography. “Mobility upon the ocean,” Mackinder remarked, was “the natural rival of horse and camel mobility” on land. In the Columbian epoch, sea power had outpaced land power, thanks to revolutions in sail and then steam. The discovery or creation of shortcuts—the Suez Canal and the route around the Cape of Good Hope—had accentuated the advantage, endowing “Christendom with the widest possible mobility of power.”³⁹ The great seafaring states, namely Britain, had encircled Eurasia, grabbing footholds in the Middle East, India, and China. They could also negate the advantages that major land powers, namely Russia, derived from occupying a central position on the world’s largest landmass.

The classic example was the Crimean War, fought between 1853 and 1856. Russia possessed interior lines—comparatively short axes of movement and communication—when it fought France, Britain, and a declining Ottoman Empire. It hardly mattered. Britain and France used command of the seas to enlarge the battlefield, threatening Russia on fronts from the Black Sea to the Baltic. Russia’s abysmal transportation infrastructure—the empire lacked railways south of Moscow—prevented it from concentrating its forces effectively. It took three weeks for allied troops to deploy from their home countries to the Crimean Peninsula; it took three months for Russian troops stationed near Moscow to move south. An allied naval blockade strangled Russian grain exports and sent the government spiraling toward bankruptcy.⁴⁰ The inferior mobility of land power sealed Russia’s humiliation, just as the superior mobility of sea power had enabled Britain’s global expansion.

Now, however, the pendulum was swinging back. The wars of German unification, from 1864 to 1871, had revealed how a dense network of railways could enable battlefield victory and geopolitical revolution. Prussia, guided by Bismarck and the vaunted General Staff, had expertly used its railway system to defeat its enemies by rapidly assembling overwhelming concentrations of force.⁴¹ The Trans-Siberian Railway, nearly finished when Mackinder delivered his lecture, might make it possible to move armies and supplies on a far larger scale.

“True, that the Trans-Siberian railway is still a single and precarious line of communication,” Mackinder allowed, “but the century will not be old before all Asia is covered with railways.”⁴² Nor would it be long before Russia was ready to rumble. A once-backward empire was now propelling itself forward; in 1900, Russia produced fifty times as much coal and 2,000 times as much steel as it had in 1860.⁴³ It was tightening its grip on areas from the Caucasus to Central Asia to Siberia. “The spaces within the Russian Empire and Mongolia are so vast, and their potentialities in population, wheat, cotton, fuel, and metals so incalculably great,” said Mackinder, “that it is inevitable a vast economic world, more or less apart, will there develop.”⁴⁴

All of which raised the possibility that a mighty, centrally located state could grab control of the Eurasian landmass. “The Pivot region of the world’s politics,” Mackinder hypothesized, was “that vast area of Euro-Asia which is inaccessible to ships, but in antiquity lay open to the horse-riding nomads, and is today about to be covered with a network of railways.”⁴⁵ Whereas Genghis Khan’s armies had used horses to sweep across Eurasia, a new generation of conquerors would ride the iron horse to glory.

Any Eurasian hegemony was likely to be dark and brutal, thanks to a third development: the modernization of tyranny. Tyrannies had always existed, indeed predominated, but the twentieth century saw something more pernicious: a coterie of countries that fused extreme repression, industrial dynamism, and violent expansion. There were hints of this in 1904; Mackinder was chiefly concerned about a Russian Empire that clung to illiberalism and monarchy even as it modernized economically, followed by a Germany that fused an imperial autocracy with competent bureaucracy and industrial heft. Yet it would be the Bolshevik regime, after it seized power in 1917, that provided Mackinder with a clearer glimpse of the future: a remorseless, well-organized police state that pursued messianic projects at home and abroad.⁴⁶ That revolution showed, as would the fascist powers of the 1930s and 1940s, how the most horrific forms of political violence and the most fantastic dreams of Eurasian expansion were parts of the same totalitarian whole.

The consequences of such expansion would be not regional but global. The consolidation of Eurasia under a hostile power could threaten even countries protected by oceanic moats.

Eurasia, Mackinder pointed out, was three times the size of North America. In the early 1900s, it possessed two-thirds of the world’s population and most of its industrial power. A country or group of countries that dominated Eurasia would be far stronger than any rival; it would be invulnerable to blockade or attack from the sea. Dominant land power would then make for dominant sea power; freed from threats on its borders, a Eurasian behemoth could build navies without match. “The oversetting of the balance of power” within Eurasia, warned Mackinder, would fatally threaten the balance of power beyond it, for this “would permit of the use of vast continental resources for fleet-building, and the empire of the world would then be in sight.”⁴⁷ Or, as Mackinder would later reformulate his thesis: “Who rules the Heartland rules the World-Island; whoever rules the World-Island commands the World.”⁴⁸

Thus Mackinder’s final insight: that the main event in global politics would henceforth be fateful fights between onshore aggressors and offshore balancers. Continental powers—here Mackinder eyed Russia, perhaps in league with Germany—would seek to rule the great Pivot Area as well as the “Inner Crescent,” that ring of countries, from China to India to Western Europe, around the Eurasian core. Offshore maritime powers making up an “Outer Crescent” would try to hold the balance by supporting Eurasian “bridge heads,” such as France and Korea, and harassing an aspiring hegemon on land and at sea.⁴⁹ As Eurasian powers pushed outward, enemies within and beyond that continent would struggle to pen them in.

In many ways, Mackinder was predicting a grim future, one in which the Eurasian rim was once again threatened by a “widespread despotism” emanating from the center. Yet there was, at least, a suggestion that such struggles might be constructive. A “repellant personality” had the benefit of energizing and uniting his enemies; a strong, vibrant Europe had been forged between the rival pressures exerted by “Asiatic nomads,” or Mongols, pressing from the east and “pirates of the sea,” or Vikings, circling to the north and west. “Neither pressure was overwhelming,” Mackinder said, “and both therefore were stimulative.”⁵⁰ Perhaps new Eurasian pressures could unleash new forms of creation.

Mackinder’s argument wasn’t cut from whole cloth. an unapologetic synthesizer, he borrowed from contemporaries such as Lord Curzon, a future British foreign secretary, and the writer H. G. Wells.⁵¹ The lecture was a product of its time in another way; Mackinder ended by warning that the Chinese might constitute the “yellow peril to the world’s freedom” if their territory were ever effectively administered by someone else. Whether or not they objected to his racism, those who encountered his thesis, either that night or later, did probe his ideas.⁵²

Hadn’t the Columbian epoch seen its own runs at European supremacy, from Philip II, Louis XIV, and Napoleon? Might air power—the Wright brothers had made their famous flight the year before—someday overshadow land and sea power alike? Was poverty-stricken Central Asia, a key part of the Pivot area, some great strategic prize? Was Russia, a late-developing country seething with political instability, the next geopolitical juggernaut?⁵³

The critics had a point, for the moment, about Russia. The completion of the Trans-Siberian Railway did cause a clash with an offshore rival; the Russo-Japanese War began weeks after Mackinder spoke. But if the start of that conflict made Mackinder look prescient, the ending didn’t. Russia suffered a crushing defeat, which precipitated an unsuccessful revolution that previewed a successful one. The railway, it turned out, was enough to provoke a war but not to win it; its single track could not adequately reinforce the tsar’s battered armies in the Far East.⁵⁴ When Russia tried, instead, to send its Baltic fleet around Eurasia, those fatigued, barnacle-encrusted ships were slaughtered in the Tsushima Strait. For two generations thereafter, attempts at Eurasian domination came not from a Pivot state pushing outward but from Crescent powers—Germany and Japan—that struck into the Eurasian Heartland while also striking across the neighboring seas.

Yet if Mackinder had his share of misfires, his central argument was a hit. His lecture was an example of what Prussian military theorist Carl von Clausewitz called coup d’oeil, or “stroke of an eye”—the ability to glance at a chaotic battlefield and discern its vital rhythms.⁵⁵ Eurasia and the adjoining waters were about to become killing fields for many of the reasons Mackinder enumerated. Helping to hold the line, ironically, would be a country that had accomplished what he feared.

Mackinder wasn’t the only big brain trying to make sense of a turbulent age. His lecture was part of a larger debate over strategy and survival in the contemporary world. That debate played out over decades; it unfolded on both sides of the Atlantic. It also intersected with another storyline of the Eurasian century—the rise of a New World superpower committed to preventing consolidation of the Old.

Mackinder had alluded to this possibility in 1904 but he hadn’t done more than that, perhaps because he was ambivalent about the United States. Yes, America had grown rich and strong in a world London stabilized; British capital built the railroads, ranches, and factories that made the United States an economic heavyweight. Cultural, religious, and linguistic ties ran deep. It was common, then, for prominent Britons of Mackinder’s day to hope that a maturing Washington would join London in defending a global order that benefited them both. Americans were a “powerful and generous nation,” Joseph Chamberlain had remarked. “They speak our language, they are bred of our race. Their laws, their literature, their standing upon every question are the same as ours; their feeling, their interest in the cause of humanity and the peaceful development of the world are identical with ours.”⁵⁶ Americans didn’t always see it the same way.

The Anglo-American special relationship was a product of the twentieth century; it did not exist in the nineteenth. American nationalism had been forged in two wars against the British Empire; war scares and diplomatic disputes were commonplace for generations thereafter. If twisting the lion’s tail was popular among U.S. politicians, that’s because large swaths of the population—especially Irish Americans—disliked Britain so much. As the United States grew stronger, its belligerence was often aimed squarely at London and its lingering presence in the Western Hemisphere; in 1894–95, Washington nearly fought a war against a global superpower over an arcane boundary dispute in South America. “The United States,” Secretary of State Richard Olney thundered, “is practically sovereign on this continent, and its fiat is law upon the subjects to which it confines its interposition.” In other words, “Dear Britain: Get out.”⁵⁷

No surprise, then, that Mackinder sometimes worried that America’s rise might mean Britain’s fall. The critical thing was to keep the United States from swallowing Canada, he wrote in 1908. For “if all North America were a single Power Britain would, indeed, be dwarfed”; the new colossus would “take from us the command of the ocean” as well.⁵⁸ Dominant land power would lead to dominant sea power. If that sounds familiar, it’s because America had largely managed to accomplish on one vast continent what Mackinder aimed to avoid on another.

The United States originated, wrote historian George Dangerfield, as a “grimy republican thumbprint” in a monarchical world.⁵⁹ Far from enjoying blissful isolation, it was ringed by hostile tribes and empires. Yet it did have powerful advantages: a rapidly growing population swollen by immigrants; a territory rich with timber, minerals, and other resources; an abundance of sparsely populated space to the west; an ideology of liberty that could be as appealing to foreign peoples as it was terrifying to their rulers; an experiment in republican government that was just effective enough to exploit these other benefits. Crucially, the United States was also located across an ocean from Europe, giving it home-field advantage in the struggle for the Western Hemisphere. Not least, America possessed an intense national ambition; it was “destined by God and nature to be the most populous and most powerful people ever combined under one social compact,” future president and secretary of state John Quincy Adams wrote.⁶⁰

By Mackinder’s time, Adams looked prophetic. The United States had expanded from the Atlantic to the Pacific. It had connected that huge territory by building a transcontinental railroad and grabbing the route for the Panama Canal. American gross domestic product (GDP) had expanded forty-fold over the course of the nineteenth century; the United States had zipped past Britain as the world’s economic leader. By 1913, America’s manufacturing output—the primary marker of economic sophistication and power in the industrial age—was more than that of Britain and Germany combined. “What was a bleak and barren wilderness a hundred and some years ago,” one foreign visitor marveled, “has quickly become this splendid and magnificent new world.”⁶¹

This emerging behemoth was well on the way to dominating the hemisphere, making the Caribbean an American lake, and thereby vindicating the doctrine that Adams, under James Monroe’s name, had promulgated. Having won supremacy regionally, the United States would soon start projecting influence globally, by seizing the Philippines from Spain and building the fleet of battleships that Theodore Roosevelt would send around the world. “Movement has been [the] dominant fact” of American life, historian Frederick Jackson Turner had observed in 1893. Now that Americans had conquered a continent, their “energy will continually demand a wider field for its exercise.”⁶²

When Mackinder worried about the future of the Old World, he may have had the recent history of the New World in mind. And as the United States used its continental empire as a base for more distant excursions, it was developing an American school of geopolitics, with Captain Alfred Thayer Mahan as its dean.

Mahan wasn’t America’s first great strategist. Alexander Hamilton and John Quincy Adams had steered a young republic in a hostile world. Abraham Lincoln preserved the “last best hope of earth” by holding the union together during the Civil War. In 1860, the explorer, writer, and politician William Gilpin peered into the country’s future, arguing that America’s “intermediate geographical position between Asia and Europe . . . invests her with the powers and duties of arbiter between them.”⁶³ It was Mahan, though, who thought most systematically and wrote most prolifically about the purposes of American power on a global stage.

He was, like Mackinder, a rare creature—a naval officer who was miserable at sea. “Mahan couldn’t handle [a ship] to save his life,” a fellow officer scoffed.⁶⁴ Mahan seemed destined for mediocrity until he joined the faculty of the newly created Naval War College in 1885. The college’s president, Rear Admiral Stephen Luce, wanted a sharp mind that could produce a science of sea power, akin to what military theorist Antoine-Henri Jomini had done for land warfare. Mahan was happy to try; naval warfare, he lamented, was a critical branch of “warfare in general” but its intellectual state was “exceedingly backward.”⁶⁵ In a best-selling book, The Influence of Sea Power upon History, 1660–1783, published in 1890, and a torrent of publications over the next quarter century, Mahan used the naval rivalries of the past to seek timeless lessons about sea power and how it could best be employed.

It took a special mix of position, people, and politics to make a maritime power, Mahan believed. Sea power accrued to nations with favorable geography, in the form of long coastlines, natural harbors, and plentiful resources; favorable demography, in the form of a large population with an instinct for trade and sail; and favorable governance, in the form of a political system willing to shell out big bucks for a merchant fleet and navy. Mahan, then, was an instinctive geopolitician, who believed a country’s “natural conditions” did much to make its strategy.⁶⁶ Yet if Mackinder foresaw an age of land power supremacy, Mahanian geopolitics held that those who ruled the waves ruled the world.⁶⁷

Waterborne travel, he argued, was still the most efficient—and global—mode of transportation. An ocean was not a barrier but a “great highway . . . a wide common, over which men pass in all directions.”⁶⁸ Maritime trade was the lifeblood of national prosperity and power; a country that controlled the seas could contain and immiserate its enemies on land. The British fleet, Mahan wrote by way of historical illustration, had stymied Napoleon’s bid for global empire by pinning him within Europe and starving him of resources; its “storm-beaten ships, upon which the Grand Army of Napoleon never looked, stood between it and the dominion of the world.”⁶⁹ The same was true in every age: naval dominance would allow a country to sink the enemy’s fleet, wreck its commerce, and ruin its dreams. The essence of global influence, contended Mahan, was “the possession of that overbearing power on the sea which drives the enemy’s flag from it, or allows it to appear only as a fugitive.”⁷⁰ Or, more pithily, “Control of the sea, by maritime commerce and naval supremacy, means predominant influence in the world.”⁷¹

Mahan was a historian with a mission: he wanted Washington to build, buy, or steal the sources of power in a ruthless world. “I am frankly an imperialist,” he acknowledged, “in the sense that I believe that no nation, certainly no great nation, should henceforth maintain the policy of isolation which fitted our early history.”⁷² He supported the annexation of Hawaii, taking the Panama Canal route, and acquisition of coaling stations and colonies. He evangelized endlessly for a blue-water navy, bristling with battleships, that would allow the United States to defeat its enemies in decisive engagements far from its shores. “War, once declared, must be waged offensively, aggressively,” he wrote. “The enemy must not be fended off, but smitten down.”⁷³

This was succor for the souls of sea power enthusiasts; Mahan’s work was celebrated by Theodore Roosevelt, Winston Churchill, and Kaiser Wilhelm II. “The Emperor is familiar with all that Mahan has written,” one journalist reported.⁷⁴ Critics scorned Mahan as a shill for imperialism and war. The doctrine of sea power, wrote journalist Norman Angell, was “a doctrine of savagery.”⁷⁵ Mahan certainly doesn’t seem enlightened by today’s standards: he considered conflict a defining aspect of human behavior; his works were full of ideas that now feel toxic. Even so, Mahan was a fairly forward-thinking sort.

Mahan sought a stable, relatively open maritime system characterized by trade and interdependence, even as he recognized that the search for wealth could be a source of rivalry.⁷⁶ He thought sea power superior to land power because the former favored freedom; armies were easily turned against the populace, but navies that couldn’t “extend coercive force inland” presented “no menace to the liberties of a people.”⁷⁷ Mahan was an early proponent of the idea that democracies made better choices, over the long run, than autocracies, even as he worried that societies that honored “the freedom and rights of the individual” faced a growing danger from those that practiced “the subordination of the individual to the state.”⁷⁸ And if Mahan was an unrepentant nationalist, his solution to the intensifying rivalries of his era was a new level of international cooperation to keep Eurasia safe for the world.

That strategy started to coalesce in The Problem of Asia, a book published in 1900. The world’s largest continent, Mahan posited, was really three distinct regions: a northern zone (Russia and northern China) where cold weather and land power predominated; a southern zone (Egypt, the Arabian Peninsula, South and Southeast Asia) with warm weather and good sea lines of communication; and a “debated and debatable” zone (the Near East, Persia, Central Asia, central China) between. That zone was “debated” because it was a political disaster, populated by a decaying China and other feeble states. Strength would prey on weakness; a hulking Russia would try to blast through en route to warmer waters and longer coastlines. The “vast, uninterrupted mass of the Russian Empire” would then have hegemony from the Levant to the Pacific; it would possess a path to the world’s oceans with all the resulting influence. “Her tendency necessarily must be to advance,” Mahan wrote, “and it is already sufficiently pronounced to be suggestive of ultimate aims.”⁷⁹

Repelling this bid would require the grandest alliance humanity had seen. A coalition of powers around the Eurasian periphery and beyond must throttle Russia’s effort to control Asian markets and trade, to deny it the wealth that would underwrite geopolitical supremacy. That alliance must also exert steady pressure on Asia’s maritime flanks—the Mediterranean, the Indian and Pacific Oceans, even China’s great rivers—as a way of supporting local, land-based resistance to Russian advances. “The land power will try to reach the sea and utilize it for its own ends,” Mahan stated, “while the sea power must obtain support on land, through the motives it can bring to bear upon the inhabitants.”⁸⁰ Controlling the waters around Eurasia, Mahan believed, was the key to denying a dangerous hegemony there.

The Russian threat faded after 1905, but the basic problem did not. Japan was playing the Mahanian game; it had thrashed Russia at sea on the way to expanding its continental empire. If Tokyo ran the table in the Far East, it might turn its attention to the open Pacific. “Should war with Japan come before the Panama Canal is finished,” warned Mahan, “the Philippines and Hawaii might fall before we could get there.”⁸¹

Mahan was also eyeing Germany. Berlin “was likely to give us something to think about seriously on this side of the water” if it ever got a free hand in Europe, he had written in 1897.⁸² Britain might currently “hold Germany . . . in check,” he later explained, but should Britain falter, “the world would again see a predominant fleet backed by a predominant army,” in the hands of a German state that had not sated itself with colonies—and was thus all the hungrier for them.⁸³

So how should America respond? By going global in its statecraft. The Monroe Doctrine was no longer enough; Washington must practice a forward defense in overseas regions. Its objective, Mahan wrote, “should be political and military equipoise, not predominance.”⁸⁴ The United States could no more tolerate a Russia, or Japan, that overawed the eastern half of Eurasia than it could tolerate a Germany that overawed the western half: A hostile hegemony in either place would turn the adjoining oceans into vectors for insecurity. Official Washington was starting to agree. In 1899, the Open Door Note announced U.S. opposition to any power that would seek to dominate China economically or politically. What all this implied, for Mahan, was that America’s geopolitical future lay in alignment with British power.

Both countries needed the great maritime highway to remain open to their commerce. Both countries had a vital interest in preserving a world not fatally unbalanced by the aggregation of despotic power at its core. The two great ocean-going democracies must therefore work together to police the seas and sustain a global system in which their shared traditions of liberty could thrive. Once Americans appreciated their “duties to the world at large,” Mahan asserted, “we shall stretch out our hands to Great Britain, realizing that in unity of heart among the English-speaking races lies the best hope of humanity in the doubtful days ahead.”⁸⁵

Mahan’s analysis wasn’t always perfect. He was downright dogmatic in arguing that the “massed fleet of line-of-battle ships” was the only true form of sea power.⁸⁶ Critics in continental Europe rejoined that commerce raiding could choke off an enemy’s trade without requiring a climactic engagement of battleships; German submarines proved the point by nearly starving Britain into submission in World War I.⁸⁷ Mahan’s history was also sometimes slipshod; a great fleet may have saved Britain from Napoleonic invasion, but the master of Europe was ultimately beaten on land. Sea power alone was never enough, Mahan’s rival, the British naval strategist Julian Corbett, pointed out. “Since men live upon the land and not upon the sea,” wars were typically decided “by what your army can do against your enemy’s territory” or by “fear of what the fleet makes it possible for your army to do.”⁸⁸ Corbett was onto something. Winning global wars in the coming century would require coordinated operations in multiple domains.

What Mahan grasped, though, was that struggles for primacy in Eurasia would be profoundly influenced by struggles for control of its adjoining oceans. Moreover, the divergence between Mahan and Corbett obscured the convergence between their nations. Mahan was building an American school of strategy rooted in a doctrine of hegemonic denial. He was also laying the intellectual groundwork for an alliance that would have seemed improbable in the nineteenth century—and would repeatedly save the day in the twentieth.

Mahan was ahead of his countrymen in foreseeing an Anglo-American global order. He was also a forerunner of a larger, more professional community of strategists in the United States. Mahan was a self-trained scholar who used history, geography, and other subjects to divine the proper uses of U.S. power.⁸⁹ This was the goal of an entire academic discipline, strategic studies, that emerged in the first half of the twentieth century as America’s influence grew—and the world repeatedly collapsed around it. It took serial breakdowns of international order for America to build up the intellectual sinews of a superpower. At the heart of that endeavor was the question of what new technologies and new forms of tyranny meant for the world.⁹⁰

The study of international order is often a response to its absence; the study of strategy flourishes after its failure. In the transatlantic community, the modern academic field of international relations arose in response to World War I and the abortive peace that followed. Writers such as the British diplomat-turned-scholar E. H. Carr produced books that purported to offer a new, scientific approach to global affairs. Think tanks and graduate schools of international studies popped up to educate the elites of today and tomorrow. And amid a new “epidemic of world lawlessness,” as Franklin Roosevelt called it in 1937, there arose a new discipline dedicated to seeking security despite surging global chaos.⁹¹

Strategic studies married brains and money: It linked institutions of higher learning, such as Yale and the Institute for Advanced Study in Princeton, to philanthropies endowed by the likes of Rockefeller and Carnegie. It was a composite discipline, blending geography, history, economics, and political science; it brought the study of military issues into America’s civilian institutions.⁹² As violence engulfed Europe and Asia, the field’s leading scholars pondered what it would take for democracies to survive when their existence seemed threatened as never before. Totalitarian states were exerting “relentless pressure,” wrote IAS scholar Edward Mead Earle. It seemed doubtful that “the cherished heritage of Anglo-Saxon political freedom can be maintained in a world so thoroughly dominated by war.”⁹³

Technology and ideology had created a fundamentally new situation, Earle wrote in 1941. “The speed, range, and destructiveness of modern aircraft—particularly the bomber—have revolutionized warfare.” Meanwhile, all-powerful states were waging all-consuming conflict. “Total war is not new,” he acknowledged. “What is new is its terrifying potentialities when waged by a totalitarian government of imagination and daring, motivated by boundless ambition and fanatical nationalism, and possessed of all the technical resources of modern science and industry.”⁹⁴ Democracies needed their intellectuals, no less than their soldiers, to answer the call to arms.

Earle practiced what he preached. His weekly seminar at the IAS helped birth some of the field’s defining works, such as Bernard Brodie’s A Layman’s Guide to Naval Strategy. Earle spearheaded the writing of Makers of Modern Strategy: Military Thought from Machiavelli to Hitler, a pathbreaking book that enlisted nearly twenty scholars—including refugees from Hitler’s Europe—to educate Americans in military realities.⁹⁵ During World War II, Earle put his mind at the disposal of the Office of Strategic Services and the Allied bombing campaign; he wrote directly to President Roosevelt on how to fight Japan in the Pacific.⁹⁶ Earle’s ultimate ambition was to produce a “unified concept of Grand Strategy”—an integrated, comprehensive approach to securing America’s interests in war and peace.⁹⁷ Yet the person who came closest to doing so was Earle’s rival for primacy in the strategic studies pantheon: Nicholas Spykman.

Spykman made his reputation as founding director of Yale’s Institute for International Studies—a body created, in 1935, partly because the university’s students were overwhelmingly isolationist.⁹⁸ Born in Amsterdam and having worked as a journalist in the Middle East and Asia, Spykman was no provincial. “The murder of an Austrian Archduke brought a million soldiers to Europe, and the failure of an Austrian credit institution closed all the banks in the United States,” he commented; the world was interested in America, even if America was not interested in the world.⁹⁹ Having begun his academic career as a sociologist studying the centrality of power in domestic society, Spykman would refocus, amid the collapse of international society, on the centrality of power in global affairs.

Power, indeed, was Spykman’s obsession—which makes sense, given that he wrote at a time when the most ruthless countries were running roughshod over their neighbors. The world, Spykman explained in a series of influential writings, was “a society without a central authority”—there was no police department to call when order broke down. States, then, had no choice but to seek power at one another’s expense. Talk about the brotherhood of man was empty piety; morality would be tossed aside when it clashed with the quest for security. In an anarchic world, “states can survive only by constant devotion to power politics.”¹⁰⁰ And of the factors that shaped the struggle for power, Spykman argued, geography “is the most fundamentally conditioning . . . because it is the most permanent. Ministers come and ministers go, even dictators die, but mountain ranges stand unperturbed.”¹⁰¹

America’s geography had long made it “the most favored state in the world.”¹⁰² Its temperate climate, enormous size, abundant resources, and dense network of internal waterways had propelled it to economic primacy. Its comparatively benign surroundings—oceans and weak or friendly neighbors—allowed it to dominate its neighborhood with “power to spare for activities outside the New World.”¹⁰³ Now, however, technology was redefining distance; hostile states with modern air power could reach out and touch their rivals in devastating ways. If the railway preoccupied Mackinder, and the steamship transfixed Mahan, the shadow of the long-range bomber informed Spykman’s seminal works during World War II.

“The world is again in flames,” Spykman wrote in America’s Strategy in World Politics, a national bestseller released in 1942. “Advanced technology has created bigger and better engines for mass murder; devastation and destruction is again the ultimate purpose to which the energy of nations is being geared.”¹⁰⁴ Written after the fall of France had rocked the European equilibrium, the book was an urgent inquiry into whether the United States could preserve “an independent national life within the Western Hemisphere” if the Axis powers were able to “crush all resistance in the Old World.”¹⁰⁵ The answer, for Spykman, was no. Mackinder had asserted that a Eurasian hegemon would threaten democracies everywhere. Spykman set out, in nearly 500 pages of careful analysis, to prove the point beyond doubt.

There was nothing limited about the Axis design, he argued. Germany aimed to conquer “the European land mass from the North Sea to the Ural Mountains.” Tokyo sought “hegemony over the Western Pacific rimland from Siberia to Tasmania.” If they succeeded, the Western Hemisphere would be “surrounded by two gigantic empires controlling huge war potentials.” America’s position between two hostile continents would become a deadly trap, as Axis air power and sea power squeezed the New World from both sides. For isolationists who pointed out, correctly, that Hitler had never said he planned to invade America, Spykman had an answer: any country ambitious and brutal enough to conquer half the world would not long tolerate the existence of a powerful enemy in the other half. “There is nothing in the history of international relations or in the nature of power politics,” he wrote, to suggest that once Eurasian hegemony was achieved, “the struggle for power would automatically cease.”¹⁰⁶

Yet Spykman made a sophisticated case for intervention. He acknowledged that something like “continental defense,” a strategy based on protecting only the Western Hemisphere, was viable for a while. Even against a hostile Eurasia, a fully mobilized United States could control strategic islands in the Atlantic and the Pacific; it could harass approaching invasion fleets with naval forces and land-based air power; a massive army could defend the country’s coasts. It was impossible, former president Herbert Hoover declared, for Germany to “attack 130,000,000 people 3,000 miles overseas, who have a capacity of 10,000,000 soldiers and 25,000 aircraft.”¹⁰⁷ The problem was that this strategy had a shelf life, because the United States couldn’t actually hold all of the Western Hemisphere.

The Southern Cone—where most of South America’s population, agriculture, and resources were located—was separated from the rest of that continent by mountains and jungles. Thanks to the bulge of Brazil, it was farther by sea from New York than from France; it was beyond the reach of even America’s most formidable bombers. So as the Axis powers used their air and naval forces to control the Atlantic and Pacific sea lanes, America would lose its grip on events below the Amazon. It would have to make a “last stand” in a more confined “quarter-sphere” encompassing most of North America, the Caribbean, and South America above the bulge.¹⁰⁸ That quarter-sphere was fatally vulnerable to strangulation and eventual destruction.

Here Spykman showed himself to be a grand strategist, because his argument involved economic and political factors as much as military ones. In 1945, economist Albert Hirschman would publish a trenchant book, National Power and the Structure of Foreign Trade, showing how totalitarian states used predatory trade tactics to pull smaller countries into their grasp. An up-to-date version of Machiavelli, Hirschman wrote, would include “extensive new sections” on “quotas, exchange controls, capital investment, and other instruments of economic warfare.”¹⁰⁹ Spykman was ahead of him, showing how Germany would wield Eurasia’s resources, trade, and capital to force South American countries into economic and political subservience. The Axis nations would simultaneously use propaganda, subversion, and ideological warfare to bring proxy forces to power. They would gradually turn South America into a hostile redoubt, while using blockades and embargoes to cut the United States off from tin, copper, and other vital materials. “Military warfare in all periods of history has been accompanied by political action,” Spykman wrote. Once America was so weakened that it could not defend the quarter-sphere, its enemies would close in for the kill.¹¹⁰

The implications were stark: indifference to the fate of distant countries could jeopardize the survival of America itself. The world was not divided into “water-tight compartments,” Spykman wrote. “Only statesmen who can do their political and strategic thinking in terms of a round earth and a three-dimensional warfare can save their countries from being outmaneuvered on distant flanks.” The United States must defeat the Axis powers before they gained unstoppable momentum—and then undertake a permanent campaign to keep Eurasia fragmented. Washington might even have to revive a defeated Germany to prevent the Soviet Union from taking its place: “A Russian state from the Urals to the North Sea can be no great improvement over a German state from the North Sea to the Urals.”¹¹¹ Geopolitics was not a task for the morally squeamish or sentimental. The enduring requirements of U.S. security were preponderant power in the Western Hemisphere and a balance of power everywhere else.

But which parts of Eurasia mattered most? This was a long-running point of contention. Mackinder had imagined a peerless land power using the Pivot area as a springboard. Mahan saw sea power as real power and focused on the struggle for the Pacific and Indian Oceans. Spykman offered his own twist, in a book, The Geography of the Peace, that appeared after his life was cut short by illness, in 1943. The real danger, he suggested, came not from a Pivot covered with permafrost. It came from the Eurasian Rimland, that “vast buffer zone of conflict” where sea power and land power met head-on.¹¹²

“Siberia is practically empty of people while the Rimland sections in Europe, India, and China are crowded,” Spykman wrote. “History tells us that it is in these latter regions rather than in the former that great civilizations and world-powerful states have existed.” These areas, roughly equivalent to Mackinder’s Inner Crescent, were home to Eurasia’s most economically dynamic, densely populated countries. They were adjacent to its vital “inner seas”—bodies such as the Mediterranean, South China Sea, and East China Sea. These waterways and not the open oceans carried most of the world’s seaborne trade, Spykman argued; they controlled maritime access to Eurasia itself. It was no coincidence that two world wars had seen Germany and Japan, two Rimland powers, seek mastery of the industry-rich peripheries of Eurasia, while also reaching into the adjoining waters. Nor would Spykman have found it odd that today’s U.S.–China rivalry is playing out primarily in the interior waterways—the East China Sea, the South China Sea, the Taiwan Strait—of the most economically important region.

Spykman’s most famous contribution was thus a partial inversion of Mackinder. The Mackinder Doctrine was that control of the Heartland led to control of the world. The Spykman Corollary was that “who controls the Rimland rules Eurasia; who rules Eurasia controls the destinies of the world.”¹¹³

This point had implications for military strategy and the long-running land power–sea power debate. Since the Rimland was accessible by both water and land, fights for dominance there would not be straight-up battles between maritime powers and continental powers. They would be clashes of an amphibious nature. Offshore powers needed sea and air control just to reach Eurasia, but they also needed powerful armies on land to beat down their enemies there. “Sea and air power,” wrote Spykman, echoing Corbett, were “the instrumentalities to achieve decisions on land.”¹¹⁴

Spykman wasn’t for everyone. His unrelenting focus on power was dark; his apparent amorality could be striking. Spykman’s work, wrote Earle in one sour review, was sometimes savaged as “a primer for a new American Prussianism.” Earle didn’t go that far, but he was appalled by Spykman’s suggestion that the best guarantee of American security was a Eurasia forever mired in division. “At the end of the war the only choice we may face is that between a more stable organization and the end of all organization, between some sort of order and complete anarchy,” he wrote. “The balance of power may well land us all in a crematory.”¹¹⁵

Yet Spykman was right that Washington would eventually use a de-Nazified Germany to contain Moscow. His wartime writings were visionary in other ways as well. Spykman provided the most nuanced case for why, exactly, a consolidated Eurasia could prove so deadly for even a strong and distant America—an argument that resonated with U.S. policymakers through World War II and the Cold War. He illustrated how totalitarian states were practicing a totalizing approach to warfare. When George Kennan, during the early Cold War, warned that such states would employ “varieties of skullduggery . . . as unlimited as human ingenuity itself, and just about as unpleasant,” he was learning from Spykman.¹¹⁶ Even the devil’s morality Spykman preached wasn’t quite what it appeared.

“All civilized life rests . . . in the last instance on power,” he wrote; any society that ignored that reality was destined for oblivion.¹¹⁷ The fundamental question of strategic studies was how democracies could maintain their way of life in a terrifying age of global war. Spykman’s answer was, by playing geopolitics remorselessly—and persistently—enough to salvage a world in which liberal institutions might endure.

Whatever their differences, Mackinder, Mahan, and Spykman were members of a democratic school of geopolitics. Their goal was to craft strategies that would allow free nations to flourish. Yet there was also an authoritarian school of geopolitics, which put the discipline to very different ends. For these thinkers, Mackinder’s vision—a world with a tyrannical Eurasia at its center—was not a nightmare to be averted. It was a dream to be achieved.

Maritime powers, writes historian S. C. M. Paine, have the option of basing their security on economic prosperity, which allows them to pursue positive-sum strategies rooted in trade and cooperation. Continental powers exist in cramped, cutthroat conditions, where the surest route to safety may be vivisecting their neighbors. For similar reasons, democracy was historically more likely to take root in insular (or effectively insular) countries that didn’t need large armies than in continental states that did. Oceans promoted economic and political openness; cramped landmasses were laboratories for aggression and tyranny.¹¹⁸ So it makes sense that the democratic school of geopolitics was an Anglo-American creation, while the authoritarian school arose in continental Europe.

This latter school was, in some respects, the original: the term “geopolitics” was first associated with Swedish intellectual Rudolf Kjellén and German geographer Friedrich Ratzel in the late nineteenth and early twentieth centuries. These thinkers were deeply influenced by social Darwinism; they saw nations as living organisms that must expand or die, and they defined nationhood in racial terms. The resulting form of geopolitics, writes one scholar, was “vindictive and expansionist.” It prioritized the coercive quest for lebensraum, or “living space,” a term Ratzel coined; it blossomed in countries, such as imperial Germany, where expansionist visions and illiberal values went hand in hand.¹¹⁹ Geopolitics tempered by democracy was stark but rarely evil. Geopolitics with an autocratic bent was poison, pure and simple.

The epitome of this approach was the “Munich school,” led by General Karl Haushofer. Haushofer had been an artillery commander in World War I. After Germany’s defeat, he participated in right-wing paramilitary organizations while starting a new career as an academic. By the late 1920s, Haushofer’s magazine on geopolitics was selling up to 500,000 copies annually; monthly radio broadcasts amplified his message.¹²⁰ The general was more prolific than penetrating; he wrote some forty books and 400 articles, many of which were rambling, repetitive, and mutually contradictory. His message, though, was well matched to a country that felt humiliated by the Versailles settlement—and to a Nazi leadership seeking intellectual legitimacy for revolutionary designs.

For Haushofer, geopolitics was expansion. Germany, thanks to its “ordeal of ruthless mutilation” after World War I, had been pinned into intolerable confines. Its only response was to “emerge out of the narrowness of her present living space into the freedom of the world.” Germany must carve out an autarkic imperium encompassing Europe and Africa. Other oppressed, have-not countries—especially the Soviet Union and Japan—would do likewise across the remainder of Eurasia and the Pacific. Only by consolidating such “pan-regions” could the ravenous revisionist states overmatch their enemies, namely the United Kingdom; only by working together could they prevent Britain from playing divide-and-conquer. “Never again,” wrote Haushofer in 1939, should Germany and Russia let “ideological conflicts” set them against each other. The goal of Haushofer’s geopolitics was a Eurasia ruled by an autocratic alliance.¹²¹

There was no chance, and no pretension, this could be accomplished without murder and mayhem. The world, wrote Haushofer, needed “a general political clearing up, a redistribution of power.” The young Eastern European countries lying athwart Germany’s path were “state fragments” that “have no longer a right to exist.”¹²² Haushofer would endorse German aggression in the late 1930s and early 1940s, even as it became clear that this involved killing millions in the “living space” Berlin desired.

Haushofer’s writings seem like an upside-down version of Mackinder, because that’s exactly what they were. Mackinder had worried that a continental hegemon could outpace Great Britain; Haushofer wanted to accomplish exactly that. Haushofer carefully read and liberally borrowed from Mackinder’s works; he even explicitly credited the idea of a Nazi–Soviet alliance to Mackinder, who as early as 1904 had worried that such a combination might be the ruin of the world. “Where does world history say that one may not learn from the enemy?” Haushofer crowed in 1939. “Russia and Germany both lost the [last] war because they fought on opposite sides. It took . . . a much longer time than Sir Halford Mackinder had expected, for the Germans and Russians to find that out.”¹²³ Mackinder, it turned out, was the “academic scribbler” influencing Haushofer, who influenced none other than Adolf Hitler.

To be sure, Haushofer’s influence on Hitler has sometimes been exaggerated. After World War II, U.S. war crimes prosecutors alleged that the former was the latter’s “intellectual godfather,” with Hitler “only a symbol and a rabble-rousing mouthpiece.”¹²⁴ During the war, the OSS described Haushofer as the man who had “transformed the study of Geopolitics . . . into an instrument of German aggression on a world scale.”¹²⁵ In reality, Haushofer’s relationship to the Nazi regime was more ambivalent, in part because he was an old-school German conservative rather than a radical National Socialist, and in part because his wife was half-Jewish. Haushofer had misgivings about Hitler’s eventual decision to attack the Soviet Union; his son would ultimately join the anti-Hitler resistance and pay for that decision with his life. Even so, Haushofer was present at the creation of Nazi geopolitics.¹²⁶

The connection was Rudolf Hess, Haushofer’s former aide and Hitler’s prison-mate after the failed Beer Hall Putsch of 1923. Haushofer introduced Hitler to his theories of geopolitics during visits to Landsberg prison. “It is a pleasure, after a full soldier’s life, to function as an old academic,” he wrote, “even if the young eagles remain behind bars for a while.”¹²⁷ As the Nazis gained influence, Haushofer maintained close contact with Hess, who became Deputy Führer; he saw Hitler as the vessel through which his intellectual rantings could become reality. Haushofer’s son, Albrecht, described his father’s views: “Whether we like it or not, they are now in the saddle; we cannot simply throw them out; thus we have the damned duty and obligation to put our shoulder to the wheel so that they will quickly lose their childhood ailments and learn to accept the right teachings.”¹²⁸

Those teachings left a mark. Haushofer may not have written Hitler’s infamous treatise, Mein Kampf, but he certainly influenced it. Central arguments—the supposed illogic of Germany’s interwar borders, the imperative to find living space in the east, the importance of eliminating European rivals—were “pure Haushofer,” historian Holger Herwig writes.¹²⁹ “Only an adequately large space on this earth assures a nation of freedom of existence,” Hitler asserted in one passage. “Hence, the German nation can defend its future only as a world power.”¹³⁰ Hitler’s later advocacy of a continental empire as an answer to British and American power also echoed his mentor’s ideas. As the geopolitical theorist Robert Strausz-Hupé observed, “Hitler found in Geopolitik a coherent explanation as to how world powers had developed in the past and how Germany could assume her place in the historic procession of great states.”¹³¹ Haushofer cheered loudly from the sidelines as annexations, invasions, and atrocities followed. The Führer, he proclaimed, was “a Charlemagne,” a practitioner of “geopolitical mastery.”¹³²

It didn’t end any better for the old academic than for the young eagle. By 1940, Haushofer realized that he had encouraged forces he could hardly control. Karl and Albrecht quietly sent out feelers to acquaintances in England about ending the war Hitler had started.¹³³ Those failed, and the Haushofers lost influence when Hess fled Germany for Scotland on a one-man peace mission in 1941. The father quietly grew more alienated; the son, having conspired to assassinate Hitler in 1944, was executed by the Führer’s henchmen as defeat impended. Karl Haushofer then killed himself while under investigation for war crimes by the Allies. “I want to forget and to be forgotten,” his suicide note read.¹³⁴

Haushofer wasn’t quickly forgotten; his legacy was to tar the very idea of geopolitics and the reputation of its foremost practitioners. Mackinder, alleged one writer in 1947, was “the man behind the man behind Hitler.” He added, not as a compliment, that “there is hardly a man or woman or child in these times whose past and future is not in some degree touched by the ideas for which Mackinder stood.”¹³⁵ This was terribly unfair to Mackinder, who abhorred Hitler and all he represented. But it was true that there were darker elements to geopolitics—the emphasis on power and the permanency of struggle, the willingness to make moral compromises—that aggressive autocrats would not hesitate to weaponize.

這後來也成為歐亞世紀一項令人尊敬的傳統。即使在今天，當暴君及其追隨者利用地緣政治原則為激進擴張辯護時，他們仍然遵循豪斯霍弗的傳統——而且，諷刺的是，他們也受到了麥金德的影響。

以亞歷山大·杜金為例，這位知識分子因其對俄羅斯復興的理論構想而聞名。與豪斯霍費爾一樣，他也是麥金德的理論追隨者。蘇聯解體後，杜金運用麥金德的理論來解釋一個新帝國如何從舊帝國的廢墟中崛起。

杜金認為，以美國為首的「大西洋主義」聯盟正試圖將其墮落的自由主義價值強加於世界各地，對俄羅斯構成生存威脅。莫斯科的最佳應對之策是「親手重建俄羅斯的歐亞大陸未來」。透過重新掌控前蘇聯加盟共和國，並與其他不滿的國家結盟，俄羅斯可以建立一個足以挫敗超級大國的強大集團。他寫道：「俄羅斯的心臟地帶」是「一場新的反資產階級、反美革命的舞台」。 「歐亞帝國的建立將基於共同敵人這一根本原則：拒絕大西洋主義，對美國進行戰略控制，並拒絕讓自由主義價值觀支配我們。」^¹³⁶

從1990年代開始，杜金在俄羅斯軍方內部的影響力與日俱增，他的地緣政治著作成為必讀書目。他似乎也有些瘋狂；2022年，他的女兒在一場汽車炸彈襲擊中喪生，據推測，這場襲擊是由烏克蘭情報人員策劃的，目標是杜金本人。之後，他聲稱「我們的帝國」是女兒小時候最早學會的詞語之一。 ^¹³⁷很少人會對安德魯馬歇爾做出同樣的評價。這位才華橫溢、行事低調的五角大廈戰略家，以其比同僚更具前瞻性的眼光而聞名。然而，在2002年，馬歇爾的思想與杜金的理念不謀而合。他警告說，崛起中的中國可能很快就會挑戰現有的秩序。華盛頓必須做好準備，「迎接一場長期的競爭…爭奪歐亞大陸和環太平洋地區的影響力和地位。」^¹³⁸

麥金德時代的偉大地緣政治辯論影響深遠；一個世紀後，自由世界秩序的敵友雙方仍以此為指導。^麥金德及其同時代人獲得了某種程度的永生。他們的著作塑造了後世政治家的希望與恐懼。

這些思想家各自都做出了至關重要的貢獻。馬漢是英美聯盟的先知，因為他洞悉了製海權在陸域霸權爭奪中的作用。斯皮克曼指出，邊緣地帶的威脅絲毫不亞於中心地帶，在全球化時代，地理上的孤立並不能保證安全。豪斯霍弗揭露了，當地緣政治脫離民主原則時，會如何滋長罪惡。但最重要的是，這是麥金德的時代。正是由於他所揭示的種種動態，歐亞大陸才成為了地緣政治的溫床。

戰略安全閥的關閉將各大強國推向了彼此對立的境地。科技的進步縮小了歐亞大陸廣大的版圖。工業經濟的極權國家的崛起助長了侵略和征服。這一切都使得一系列潛在的歐亞霸權國家與那些自由主義超級大國針鋒相對，而這些超級大國的自由和安全都依賴於挫敗這些霸權國家的野心。麥金德的論點清晰而殘酷：種種因素正在匯聚，一場圍繞歐亞大陸乃至整個世界的持久而高風險的鬥爭即將展開。歐亞世紀的殘酷歷史將證明他的預言是多麼正確。

Chapter 1 Mackinder’s World

The Trans-Siberian Railway is a steel belt that binds two continents. Its nearly 6,000 miles of track link Moscow to Vladivostok; connecting lines run across Europe and down Asia’s eastern edge. For more than a century, the Trans-Siberian has attracted travelers who want to journey through some of the world’s most remote, and sometimes beautiful, territory: the Ural Mountains, the shores of Lake Baikal, the stunning isolation of the Russian steppe. But when it was completed in 1904, the Trans-Siberian Railway was the stuff of imperial dreams and geopolitical nightmares.¹

The tsarist government built the railway—a monumentally expensive, debt-funded project—with glory in mind. The track was meant to open huge, resource-rich Siberia to settlement and industrialization. It would enable the Russian Empire to strengthen its influence in Manchuria, Korea, and throughout the Far East. The railway, argued its champion, Count Sergei Witte, would catalyze foreign expansion and domestic consolidation; it “would not only bring about the opening of Siberia, but would revolutionize world trade, supersede the Suez Canal as the leading route to China, enable Russia to flood the Chinese market with textiles and metal goods, and secure political control of northern China.”²

The Trans-Siberian Railway changed the world, just not as Witte intended. Japan, Russia’s rival in the region, understood exactly what was coming. Trains can carry troops, so strengthened transportation links to Northeast Asia would allow the tsarist empire to impose itself in Tokyo’s backyard. “The day the Trans-Siberian Railroad is completed will be the day that crisis comes to Korea,” one Japanese commander predicted, “and when crisis comes to Korea, all the Orient will face upheaval.”³ Tokyo wasn’t about to let that happen. Just months before the final section of track was completed, Japan launched a surprise attack on the Russian fleet at Port Arthur, starting the first great-power war of the twentieth century—a fight for imperial supremacy in Northeast Asia.

It was a portent of things to come. The Trans-Siberian Railway was a flashpoint throughout the bloody epoch that followed.

The modernization of the Russian rail network, with the Trans-Siberian as its backbone, helped bring on World War I by convincing German officials that a lumbering Russian steamroller would soon be able to mobilize with modern speed. “The big Russian railway constructions,” Kaiser Wilhelm II brooded, were “preparations for a great war.”⁴ Rival Russian factions battled over the railroad during the civil war that World War I set off; concern that the Bolsheviks—or Germans—might control the tracks then motivated a hapless intervention by Washington and other powers. State Department officials left little doubt about the goal of that expedition; “the maintenance, operation and control of the Trans-Siberian Railroad” was its “initial and preeminently important step.”⁵

The same railway had a starring role in the next world war. Between 1939 and 1941, the Trans-Siberian was an economic highway between the Axis powers, with the Soviet Union—then effectively allied to Germany—as the intermediary. By spring 1941, the railroad was carrying 300 vital tons of rubber from Japan’s growing empire to Germany each day.⁶ After Hitler turned on Stalin in June 1941, the railroad helped seal the alliance that ensured Germany’s defeat. Huge quantities of American Lend-Lease aid traveled the Trans-Siberian from Vladivostok to Stalin’s European front.⁷ And decades later, as Vladimir Putin was getting ready to invade Ukraine, the railway set the stage for another gruesome showdown.

During a slow, menacing buildup for Europe’s largest conflict since World War II, Putin used the Trans-Siberian to shuttle military assets from one side of Eurasia to the other. Military trains carried tanks, trucks, infantry, and missile launchers from the Russian Far East to the Ukrainian border. One unit that made the trip, the 64th Separate Motorized Rifle Brigade, partook in the rape, torture, and murder of civilians in Bucha, the suburb of Kyiv whose name became synonymous with Russian depravity.⁸ “There are maniacs who enjoy killing a man,” one member of that unit acknowledged. “Such maniacs turned up there.”⁹ In 1891, Tsar Alexander III had declared, “Let a railroad be built.” Over 130 years later, the Trans-Siberian was still a conduit for conflict.¹⁰

There’s a good reason for this. Geography is stubborn; barring expansion or contraction, a country is where it is. Developments that alter geography, or ease the constraints it imposes, can thus profoundly change world affairs. The digging of the Suez Canal turbocharged the building of European empires in Asia and Africa by slashing travel times between metropole and periphery. The construction of a transcontinental railroad in the nineteenth century helped make the United States a global superpower in the twentieth, by giving it mastery of North America from coast to coast. The Trans-Siberian Railway made it possible to move armies rapidly across Eurasia; it previewed technological revolutions that would enable bids for conquest vaster still. So the completion of the Trans-Siberian augured an era of violent collisions on a global scale.

Sir Halford Mackinder saw that era coming, in a lecture he delivered when it was just about to begin. Mackinder’s ideas previewed the basic patterns of conflict in the coming century. They thrust him into a grand debate, spanning countries and decades, over geopolitics and strategy in the modern age. And they had a lasting impact on those who sought to preserve a world fit for human freedom—as well as those who sought to destroy it. All the greatest wars and rivalries of the Eurasian century were contests to rule Mackinder’s world.

“Practical men who believe themselves to be quite exempt from any intellectual influence, are usually the slaves of some defunct economist,” John Maynard Keynes once wrote. “Madmen in authority, who hear voices in the air, are distilling their frenzy from some academic scribbler of a few years back.”¹¹ Keynes was saying that ideas precede policy, even if policymakers don’t realize it. That’s a good way to understand the life and legacy of Halford Mackinder.

In fairness, Mackinder was no obscure scribbler. Born in 1861 in Gainsborough, in the English midlands, he would live until 1947—a period encompassing the apogee of European imperialism and British power, the descent into two world wars, and the onset of decolonization and the Cold War. As a boy, Mackinder read the news that Bismarck’s Prussia had thrashed France and unified Germany, and wondered what the consolidation of a rising empire in the heart of Europe would bring. It was a remarkable time to be alive, and over a professional life spanning six decades, Mackinder did remarkable things.¹²

He was well equipped for ambitious and adventurous pursuits. The son of a doctor, Mackinder was educated at boarding school and then Oxford. He had a talent for languages, learning French and German, and a passion for exploration that would take him—physically or intellectually—around the globe. Mackinder may have been, as he put it, “rather a lonely boy” with an affinity for books and maps, but he was strong, athletic, and intellectually mature.¹³ At university in the early 1880s, he cultivated his passions for geology and history, for public speaking and intellectual debate at the Oxford Union, and for service to the British Empire, through the Oxford Army Volunteer Reserve and the University Rifle Corps. After graduation, Mackinder first sought to become a lawyer, before beating a less conventional path.

Having taken to lecturing on geography for extra money, Mackinder turned his side hustle into an Oxford professorship at the age of twenty-five, on the strength of a talk that helped establish that subject as an academic discipline. He would play an important role in launching a series of prestigious academic institutions—the Oxford School of Geography, Reading University, and the London School of Economics—and he became a public intellectual who wrote on subjects ranging from tariff policy to the causes of war and peace. Mackinder then pivoted into politics, representing the Camlachie district of Glasgow in the House of Commons from 1910 to 1922. After World War I, he tried his hand at statecraft, serving as British High Commissioner for South Russia and attempting to sort out the chaos sown by war and revolution.

After losing his seat in Parliament in 1922, Mackinder threw himself back into public service, chairing unsexy but important bodies such as the Imperial Shipping Committee, meant to knit the British Empire together even as centrifugal forces were tearing it apart. For good measure, Mackinder was an accomplished mountaineer who led the first successful ascent of Mount Kenya. That climb was “a really serious mountaineering feat,” a contemporary noted—even if it was also a deadly misadventure, marred by rumors (never proven) that Mackinder was involved in the murder of mutinous African porters.¹⁴

Mackinder was a classic polymath; he had several careers wrapped into one. “I do not admit to having been a rolling stone, because I have generally known where I was going,” he remarked, “but I have certainly gathered no moss.”¹⁵

He had, alas, known disappointment. Mackinder didn’t accomplish all he intended. His highest aspiration was to be a heavy hitter in British policy—a man of ideas who was also a man of action. “If he got his foot on the ladder he might go far towards the top,” one observer predicted in 1902, “especially as there is an absence of able young men.”¹⁶ Climbing Mount Kenya proved easy by comparison.

Mackinder was not a natural politician, in part because of his abstract intellectual style. He never became a member of the Cabinet or otherwise really broke into the highest levels of the policy elite. His stint as High Commissioner was short and inglorious; his most comprehensive statement on foreign policy, a book titled Democratic Ideals and Reality, was mostly ignored for a generation after it was published. Mackinder, wrote his friend Leo Amery, had a “more forceful personality and a more powerful brain” than his higher-flying colleagues. But he “never quite made the mark once expected by him.”¹⁷

Yet if Mackinder failed to get his hands firmly on the levers of power, he still left a lasting imprint. Mackinder prided himself on his ability to think big—to see beyond the present crisis and grasp the historical forces at work. It was essential, he wrote, that leaders of a democracy “be able easily and happily to roam in thought over the surface of the world, thinking in millions, thinking in ages.”¹⁸ Those who heard him speak on the subjects he knew best never doubted his ability; decades later, one colleague recalled how Mackinder, so “tall, erect, distinguished,” would enrapture his students by delivering, “in his sonorous voice, without ever a note, a perfectly argued and presented synthesis.”¹⁹ Where Mackinder most excelled was in explaining geopolitics, a discipline focused on the relationship between geographical realities and political power.²⁰

In his field-defining lecture, “On the Scope and Methods of Geography,” Mackinder insisted that the discipline involved more than the mere cataloguing of physical facts; such a dry endeavor “must always fail to attract minds of an amplitude fitting them to be rulers of men.”²¹ Mackinder’s version of geography—political geography—involved studying how the earth’s features affected the behavior of peoples and societies across the long arc of history, and how their behavior, in turn, reshaped the physical environment. This required imagination and sweep: “Humdrum detail is the greater part of every science, but no science can satisfy the mind which does not allow of the building of palaces out of its bricks.”²² Few built mental palaces more majestic than Mackinder’s.

One of his most-read books showed how Britain’s geography and geology—the combination of its resource endowments and position off Europe’s coast—had turned a small island nation into a wealthy, liberal sea power with a peerless empire. Another volume explained how the features of the Rhine River Valley had influenced the long contest to rule Central Europe.²³ The vital theme of Mackinder’s work was that geography profoundly shaped the timeless struggle for power: It wasn’t quite destiny, but it was a reality no good strategist could ignore. “Man and not nature initiates,” he asserted, “but nature in large measure controls.”²⁴ Which meant that training its people and leaders in a geographical way of thinking was essential for Britain to thrive, especially as the world began to change in epochal ways.

The world of Mackinder’s upbringing was a world of ubiquitous British power. London was the global hegemon of the nineteenth century; its influence reached into every inhabited continent. The Royal Navy patrolled the seas, allowing commerce to boom and an age of globalization to ignite. Indeed, London presided over what we would now call a liberal international order; the first great international expansion of democracy happened when British-style representative institutions took hold amid British primacy.²⁵ Notwithstanding some nasty but mostly localized wars, Europe was enjoying its long post-Napoleonic peace, allowing London to avoid continental entanglements and bask in “splendid isolation.” The symbolic apex of British splendor was Queen Victoria’s Diamond Jubilee in 1897, which showcased the world’s best warships and imperial troops from around the globe. The atmosphere, recalled historian Arnold Toynbee, was, “Well, here we are on top of the world, and we have arrived at this peak to stay there—forever!”²⁶

In reality, British power—and international stability—were slipping away. Britain had lost one crucial pillar of its hegemony; by 1890, it no longer had the world’s largest economy. A cohort of rising powers—Prussia (later Germany), America, and Japan—were asserting their interests and reordering their regions through short, sharp wars. France and Britain almost came to blows in 1898 over imperial visions that collided in Sudan; by 1899, London was embroiled in an ugly colonial scrap against the Boers in southern Africa. Russia, Britain’s long-standing rival along fault lines from Eastern Europe to South Asia, was building up its economy and military. The British Empire was beset by crises everywhere. As Colonial Secretary Joseph Chamberlain put it, “The weary Titan staggers under the too vast orb of his fate.”²⁷

Geopolitical upheaval went hand in hand with sharpening ideological conflict. Clashes between opposing ideas, between competing systems of government, are as old as history. Such clashes had, however, temporarily subsided after the ideological flames ignited by the French Revolution were finally extinguished. The countries that defeated Napoleon and established the Concert of Europe in 1814–15 had shared a preference for order, which trumped, for a time, their different conceptions of justice.²⁸ As the Concert broke down in the late nineteenth century, ideological tensions flared anew.

The Great Game was not just a rivalry between voracious empires; the stark and widening gap between a democratizing Britain and a despotic Russia made that contest one of values, too. “We are not of the same make,” the British minister in Tehran wrote. “We differ as our governments differ.”²⁹ The leaders of another British rival, Germany, had committed themselves to seeking greatness through autocracy and coercion. Germany’s chancellor, Otto von Bismarck, had once declared that history would be made not “by speeches or majority decisions” but “by blood and iron.” Prussia had become strong, he explained, “not through liberalism and free-thinking” but through the guidance of resolute authoritarians who acted with “ruthless courage.”³⁰ A key question of the twentieth century, Mackinder and many contemporaries believed, was whether liberal states or their illiberal challengers would set the rules of the road.

Even war itself had changed. Gone were the languid, desultory conflicts that Europe’s cash-strapped monarchies had waged in an earlier era. The French Revolution had opened an era of total war—contests in which modern states, driven by fierce nationalism and boasting sophisticated bureaucratic and financial capabilities, harnessed society’s energies to seek the outright destruction of their foes. In the 1860s, the U.S. Civil War had demonstrated how combatants could mobilize manpower, money, and industrial muscle on a scale previously unheard of, to fight wars longer, more destructive, and more consuming than before. Even the smaller, shorter wars that followed—the wars of German unification, the Sino-Japanese war, the Boer War—displayed the devastating effects of modern firepower and mass-produced weapons. As the international system grew more disordered, great-power collisions grew more devastating.³¹

Finally, by the dawn of the twentieth century the world was getting more crowded, claustrophobic. Progress was partly to blame; steamships, railroads, and telegraphs were thrusting people and continents together. Conquest was another culprit. The rapid-fire European imperial aggrandizement of the late nineteenth century, what one foreign minister called a “veritable steeplechase for colonial acquisitions,” had created mega-empires—with Britain’s the largest—that covered the globe. Influenced by social Darwinism and the notion that only the fittest would survive, strategists throughout Europe and beyond insisted that countries must expand, engorging themselves with lands and resources, or be devoured by their rivals. Strong states “assert themselves in the universal economy of nature,” wrote one retired German general. “The weaker succumb.”³² Mackinder’s world was becoming a tinderbox intellectually as well as politically.

The opening decade of the 1900s was a moment of tectonic change in world politics—even if it was, understandably, difficult for contemporary observers to make out just what was happening and why. That was Mackinder’s task when he visited the Royal Geographic Society on the evening of January 25, 1904, to deliver a lecture called “The Geographic Pivot of History.”

Few strategic texts of the modern era were more seminal; Mackinder’s lecture influenced generations of military, diplomatic, and political leaders. Yet you might not have guessed it at the time.

The talk wasn’t an immediate hit; one attendee “looked with regret on some of the space which is unoccupied here.”³³ Perhaps that was because it was a frigid January night. Or perhaps it was because Mackinder’s lecture combined vague abstraction, meandering narration, distant history, and mountains of geographical detail. The talk featured a long, if graceful, discussion of rivers, steppes, peaks, and monsoon lands; it was full of concepts (“Pivot Area,” “Inner Crescent,” “Outer Crescent”) that then probably seemed obscure. Mackinder asked a lot of his listeners. He also delivered a lot, for the analytical heart of his lecture was a penetrating discussion of the forces producing a Eurasian century.

First was the end of what Mackinder termed the “Columbian epoch”—that 400-year age of European exploration and conquest that began with the discovery of the Americas. “Whereas mediaeval Christendom was pent into a narrow region and threatened by external barbarism,” Mackinder explained, the Columbian epoch had seen “the expansion of Europe against almost negligible resistances.”³⁴ The major European states had mapped and divided the globe; the process had accelerated in the nineteenth century as advances in firepower, medicine, and transportation drove imperial penetrations deep into Africa and Asia. Not long after Mackinder spoke, Britain would control an empire of 31 million square kilometers; the French empire, at 12.5 million square kilometers, was twenty times larger than France itself.³⁵ Yet now the Columbian epoch was ending, a victim of catastrophic success.

There were no more worlds to conquer. Africa and much of Asia had been subjugated; the “new Europes” of Australia, Canada, and New Zealand were part of the British Empire. There was “scarcely a region left for the pegging out of a claim of ownership, unless the result of a war between civilized or half-civilized powers,” Mackinder said.³⁶ Britain had gained the most from this orgy of aggrandizement, but the implications were ominous nevertheless.

The European powers had, since Napoleon’s demise, mostly avoided all-out conflict, in part because expansion directed their aggression outward; a “long war” against less developed societies facilitated a “long peace” among the empires themselves.³⁷ Now this safety valve was closed. “Every explosion of social forces, instead of being dissipated in a circuit of unknown space and barbaric chaos, will be sharply re-echoed from the far side of the globe.” A “closed political system” would be vicious; great-power relations were becoming zero-sum.³⁸

Tensions were also rising for a second reason: technology was remaking geography. “Mobility upon the ocean,” Mackinder remarked, was “the natural rival of horse and camel mobility” on land. In the Columbian epoch, sea power had outpaced land power, thanks to revolutions in sail and then steam. The discovery or creation of shortcuts—the Suez Canal and the route around the Cape of Good Hope—had accentuated the advantage, endowing “Christendom with the widest possible mobility of power.”³⁹ The great seafaring states, namely Britain, had encircled Eurasia, grabbing footholds in the Middle East, India, and China. They could also negate the advantages that major land powers, namely Russia, derived from occupying a central position on the world’s largest landmass.

The classic example was the Crimean War, fought between 1853 and 1856. Russia possessed interior lines—comparatively short axes of movement and communication—when it fought France, Britain, and a declining Ottoman Empire. It hardly mattered. Britain and France used command of the seas to enlarge the battlefield, threatening Russia on fronts from the Black Sea to the Baltic. Russia’s abysmal transportation infrastructure—the empire lacked railways south of Moscow—prevented it from concentrating its forces effectively. It took three weeks for allied troops to deploy from their home countries to the Crimean Peninsula; it took three months for Russian troops stationed near Moscow to move south. An allied naval blockade strangled Russian grain exports and sent the government spiraling toward bankruptcy.⁴⁰ The inferior mobility of land power sealed Russia’s humiliation, just as the superior mobility of sea power had enabled Britain’s global expansion.

Now, however, the pendulum was swinging back. The wars of German unification, from 1864 to 1871, had revealed how a dense network of railways could enable battlefield victory and geopolitical revolution. Prussia, guided by Bismarck and the vaunted General Staff, had expertly used its railway system to defeat its enemies by rapidly assembling overwhelming concentrations of force.⁴¹ The Trans-Siberian Railway, nearly finished when Mackinder delivered his lecture, might make it possible to move armies and supplies on a far larger scale.

“True, that the Trans-Siberian railway is still a single and precarious line of communication,” Mackinder allowed, “but the century will not be old before all Asia is covered with railways.”⁴² Nor would it be long before Russia was ready to rumble. A once-backward empire was now propelling itself forward; in 1900, Russia produced fifty times as much coal and 2,000 times as much steel as it had in 1860.⁴³ It was tightening its grip on areas from the Caucasus to Central Asia to Siberia. “The spaces within the Russian Empire and Mongolia are so vast, and their potentialities in population, wheat, cotton, fuel, and metals so incalculably great,” said Mackinder, “that it is inevitable a vast economic world, more or less apart, will there develop.”⁴⁴

All of which raised the possibility that a mighty, centrally located state could grab control of the Eurasian landmass. “The Pivot region of the world’s politics,” Mackinder hypothesized, was “that vast area of Euro-Asia which is inaccessible to ships, but in antiquity lay open to the horse-riding nomads, and is today about to be covered with a network of railways.”⁴⁵ Whereas Genghis Khan’s armies had used horses to sweep across Eurasia, a new generation of conquerors would ride the iron horse to glory.

Any Eurasian hegemony was likely to be dark and brutal, thanks to a third development: the modernization of tyranny. Tyrannies had always existed, indeed predominated, but the twentieth century saw something more pernicious: a coterie of countries that fused extreme repression, industrial dynamism, and violent expansion. There were hints of this in 1904; Mackinder was chiefly concerned about a Russian Empire that clung to illiberalism and monarchy even as it modernized economically, followed by a Germany that fused an imperial autocracy with competent bureaucracy and industrial heft. Yet it would be the Bolshevik regime, after it seized power in 1917, that provided Mackinder with a clearer glimpse of the future: a remorseless, well-organized police state that pursued messianic projects at home and abroad.⁴⁶ That revolution showed, as would the fascist powers of the 1930s and 1940s, how the most horrific forms of political violence and the most fantastic dreams of Eurasian expansion were parts of the same totalitarian whole.

The consequences of such expansion would be not regional but global. The consolidation of Eurasia under a hostile power could threaten even countries protected by oceanic moats.

Eurasia, Mackinder pointed out, was three times the size of North America. In the early 1900s, it possessed two-thirds of the world’s population and most of its industrial power. A country or group of countries that dominated Eurasia would be far stronger than any rival; it would be invulnerable to blockade or attack from the sea. Dominant land power would then make for dominant sea power; freed from threats on its borders, a Eurasian behemoth could build navies without match. “The oversetting of the balance of power” within Eurasia, warned Mackinder, would fatally threaten the balance of power beyond it, for this “would permit of the use of vast continental resources for fleet-building, and the empire of the world would then be in sight.”⁴⁷ Or, as Mackinder would later reformulate his thesis: “Who rules the Heartland rules the World-Island; whoever rules the World-Island commands the World.”⁴⁸

Thus Mackinder’s final insight: that the main event in global politics would henceforth be fateful fights between onshore aggressors and offshore balancers. Continental powers—here Mackinder eyed Russia, perhaps in league with Germany—would seek to rule the great Pivot Area as well as the “Inner Crescent,” that ring of countries, from China to India to Western Europe, around the Eurasian core. Offshore maritime powers making up an “Outer Crescent” would try to hold the balance by supporting Eurasian “bridge heads,” such as France and Korea, and harassing an aspiring hegemon on land and at sea.⁴⁹ As Eurasian powers pushed outward, enemies within and beyond that continent would struggle to pen them in.

In many ways, Mackinder was predicting a grim future, one in which the Eurasian rim was once again threatened by a “widespread despotism” emanating from the center. Yet there was, at least, a suggestion that such struggles might be constructive. A “repellant personality” had the benefit of energizing and uniting his enemies; a strong, vibrant Europe had been forged between the rival pressures exerted by “Asiatic nomads,” or Mongols, pressing from the east and “pirates of the sea,” or Vikings, circling to the north and west. “Neither pressure was overwhelming,” Mackinder said, “and both therefore were stimulative.”⁵⁰ Perhaps new Eurasian pressures could unleash new forms of creation.

Mackinder’s argument wasn’t cut from whole cloth. an unapologetic synthesizer, he borrowed from contemporaries such as Lord Curzon, a future British foreign secretary, and the writer H. G. Wells.⁵¹ The lecture was a product of its time in another way; Mackinder ended by warning that the Chinese might constitute the “yellow peril to the world’s freedom” if their territory were ever effectively administered by someone else. Whether or not they objected to his racism, those who encountered his thesis, either that night or later, did probe his ideas.⁵²

Hadn’t the Columbian epoch seen its own runs at European supremacy, from Philip II, Louis XIV, and Napoleon? Might air power—the Wright brothers had made their famous flight the year before—someday overshadow land and sea power alike? Was poverty-stricken Central Asia, a key part of the Pivot area, some great strategic prize? Was Russia, a late-developing country seething with political instability, the next geopolitical juggernaut?⁵³

The critics had a point, for the moment, about Russia. The completion of the Trans-Siberian Railway did cause a clash with an offshore rival; the Russo-Japanese War began weeks after Mackinder spoke. But if the start of that conflict made Mackinder look prescient, the ending didn’t. Russia suffered a crushing defeat, which precipitated an unsuccessful revolution that previewed a successful one. The railway, it turned out, was enough to provoke a war but not to win it; its single track could not adequately reinforce the tsar’s battered armies in the Far East.⁵⁴ When Russia tried, instead, to send its Baltic fleet around Eurasia, those fatigued, barnacle-encrusted ships were slaughtered in the Tsushima Strait. For two generations thereafter, attempts at Eurasian domination came not from a Pivot state pushing outward but from Crescent powers—Germany and Japan—that struck into the Eurasian Heartland while also striking across the neighboring seas.

Yet if Mackinder had his share of misfires, his central argument was a hit. His lecture was an example of what Prussian military theorist Carl von Clausewitz called coup d’oeil, or “stroke of an eye”—the ability to glance at a chaotic battlefield and discern its vital rhythms.⁵⁵ Eurasia and the adjoining waters were about to become killing fields for many of the reasons Mackinder enumerated. Helping to hold the line, ironically, would be a country that had accomplished what he feared.

Mackinder wasn’t the only big brain trying to make sense of a turbulent age. His lecture was part of a larger debate over strategy and survival in the contemporary world. That debate played out over decades; it unfolded on both sides of the Atlantic. It also intersected with another storyline of the Eurasian century—the rise of a New World superpower committed to preventing consolidation of the Old.

Mackinder had alluded to this possibility in 1904 but he hadn’t done more than that, perhaps because he was ambivalent about the United States. Yes, America had grown rich and strong in a world London stabilized; British capital built the railroads, ranches, and factories that made the United States an economic heavyweight. Cultural, religious, and linguistic ties ran deep. It was common, then, for prominent Britons of Mackinder’s day to hope that a maturing Washington would join London in defending a global order that benefited them both. Americans were a “powerful and generous nation,” Joseph Chamberlain had remarked. “They speak our language, they are bred of our race. Their laws, their literature, their standing upon every question are the same as ours; their feeling, their interest in the cause of humanity and the peaceful development of the world are identical with ours.”⁵⁶ Americans didn’t always see it the same way.

The Anglo-American special relationship was a product of the twentieth century; it did not exist in the nineteenth. American nationalism had been forged in two wars against the British Empire; war scares and diplomatic disputes were commonplace for generations thereafter. If twisting the lion’s tail was popular among U.S. politicians, that’s because large swaths of the population—especially Irish Americans—disliked Britain so much. As the United States grew stronger, its belligerence was often aimed squarely at London and its lingering presence in the Western Hemisphere; in 1894–95, Washington nearly fought a war against a global superpower over an arcane boundary dispute in South America. “The United States,” Secretary of State Richard Olney thundered, “is practically sovereign on this continent, and its fiat is law upon the subjects to which it confines its interposition.” In other words, “Dear Britain: Get out.”⁵⁷

No surprise, then, that Mackinder sometimes worried that America’s rise might mean Britain’s fall. The critical thing was to keep the United States from swallowing Canada, he wrote in 1908. For “if all North America were a single Power Britain would, indeed, be dwarfed”; the new colossus would “take from us the command of the ocean” as well.⁵⁸ Dominant land power would lead to dominant sea power. If that sounds familiar, it’s because America had largely managed to accomplish on one vast continent what Mackinder aimed to avoid on another.

The United States originated, wrote historian George Dangerfield, as a “grimy republican thumbprint” in a monarchical world.⁵⁹ Far from enjoying blissful isolation, it was ringed by hostile tribes and empires. Yet it did have powerful advantages: a rapidly growing population swollen by immigrants; a territory rich with timber, minerals, and other resources; an abundance of sparsely populated space to the west; an ideology of liberty that could be as appealing to foreign peoples as it was terrifying to their rulers; an experiment in republican government that was just effective enough to exploit these other benefits. Crucially, the United States was also located across an ocean from Europe, giving it home-field advantage in the struggle for the Western Hemisphere. Not least, America possessed an intense national ambition; it was “destined by God and nature to be the most populous and most powerful people ever combined under one social compact,” future president and secretary of state John Quincy Adams wrote.⁶⁰

By Mackinder’s time, Adams looked prophetic. The United States had expanded from the Atlantic to the Pacific. It had connected that huge territory by building a transcontinental railroad and grabbing the route for the Panama Canal. American gross domestic product (GDP) had expanded forty-fold over the course of the nineteenth century; the United States had zipped past Britain as the world’s economic leader. By 1913, America’s manufacturing output—the primary marker of economic sophistication and power in the industrial age—was more than that of Britain and Germany combined. “What was a bleak and barren wilderness a hundred and some years ago,” one foreign visitor marveled, “has quickly become this splendid and magnificent new world.”⁶¹

This emerging behemoth was well on the way to dominating the hemisphere, making the Caribbean an American lake, and thereby vindicating the doctrine that Adams, under James Monroe’s name, had promulgated. Having won supremacy regionally, the United States would soon start projecting influence globally, by seizing the Philippines from Spain and building the fleet of battleships that Theodore Roosevelt would send around the world. “Movement has been [the] dominant fact” of American life, historian Frederick Jackson Turner had observed in 1893. Now that Americans had conquered a continent, their “energy will continually demand a wider field for its exercise.”⁶²

When Mackinder worried about the future of the Old World, he may have had the recent history of the New World in mind. And as the United States used its continental empire as a base for more distant excursions, it was developing an American school of geopolitics, with Captain Alfred Thayer Mahan as its dean.

Mahan wasn’t America’s first great strategist. Alexander Hamilton and John Quincy Adams had steered a young republic in a hostile world. Abraham Lincoln preserved the “last best hope of earth” by holding the union together during the Civil War. In 1860, the explorer, writer, and politician William Gilpin peered into the country’s future, arguing that America’s “intermediate geographical position between Asia and Europe . . . invests her with the powers and duties of arbiter between them.”⁶³ It was Mahan, though, who thought most systematically and wrote most prolifically about the purposes of American power on a global stage.

He was, like Mackinder, a rare creature—a naval officer who was miserable at sea. “Mahan couldn’t handle [a ship] to save his life,” a fellow officer scoffed.⁶⁴ Mahan seemed destined for mediocrity until he joined the faculty of the newly created Naval War College in 1885. The college’s president, Rear Admiral Stephen Luce, wanted a sharp mind that could produce a science of sea power, akin to what military theorist Antoine-Henri Jomini had done for land warfare. Mahan was happy to try; naval warfare, he lamented, was a critical branch of “warfare in general” but its intellectual state was “exceedingly backward.”⁶⁵ In a best-selling book, The Influence of Sea Power upon History, 1660–1783, published in 1890, and a torrent of publications over the next quarter century, Mahan used the naval rivalries of the past to seek timeless lessons about sea power and how it could best be employed.

It took a special mix of position, people, and politics to make a maritime power, Mahan believed. Sea power accrued to nations with favorable geography, in the form of long coastlines, natural harbors, and plentiful resources; favorable demography, in the form of a large population with an instinct for trade and sail; and favorable governance, in the form of a political system willing to shell out big bucks for a merchant fleet and navy. Mahan, then, was an instinctive geopolitician, who believed a country’s “natural conditions” did much to make its strategy.⁶⁶ Yet if Mackinder foresaw an age of land power supremacy, Mahanian geopolitics held that those who ruled the waves ruled the world.⁶⁷

Waterborne travel, he argued, was still the most efficient—and global—mode of transportation. An ocean was not a barrier but a “great highway . . . a wide common, over which men pass in all directions.”⁶⁸ Maritime trade was the lifeblood of national prosperity and power; a country that controlled the seas could contain and immiserate its enemies on land. The British fleet, Mahan wrote by way of historical illustration, had stymied Napoleon’s bid for global empire by pinning him within Europe and starving him of resources; its “storm-beaten ships, upon which the Grand Army of Napoleon never looked, stood between it and the dominion of the world.”⁶⁹ The same was true in every age: naval dominance would allow a country to sink the enemy’s fleet, wreck its commerce, and ruin its dreams. The essence of global influence, contended Mahan, was “the possession of that overbearing power on the sea which drives the enemy’s flag from it, or allows it to appear only as a fugitive.”⁷⁰ Or, more pithily, “Control of the sea, by maritime commerce and naval supremacy, means predominant influence in the world.”⁷¹

Mahan was a historian with a mission: he wanted Washington to build, buy, or steal the sources of power in a ruthless world. “I am frankly an imperialist,” he acknowledged, “in the sense that I believe that no nation, certainly no great nation, should henceforth maintain the policy of isolation which fitted our early history.”⁷² He supported the annexation of Hawaii, taking the Panama Canal route, and acquisition of coaling stations and colonies. He evangelized endlessly for a blue-water navy, bristling with battleships, that would allow the United States to defeat its enemies in decisive engagements far from its shores. “War, once declared, must be waged offensively, aggressively,” he wrote. “The enemy must not be fended off, but smitten down.”⁷³

This was succor for the souls of sea power enthusiasts; Mahan’s work was celebrated by Theodore Roosevelt, Winston Churchill, and Kaiser Wilhelm II. “The Emperor is familiar with all that Mahan has written,” one journalist reported.⁷⁴ Critics scorned Mahan as a shill for imperialism and war. The doctrine of sea power, wrote journalist Norman Angell, was “a doctrine of savagery.”⁷⁵ Mahan certainly doesn’t seem enlightened by today’s standards: he considered conflict a defining aspect of human behavior; his works were full of ideas that now feel toxic. Even so, Mahan was a fairly forward-thinking sort.

Mahan sought a stable, relatively open maritime system characterized by trade and interdependence, even as he recognized that the search for wealth could be a source of rivalry.⁷⁶ He thought sea power superior to land power because the former favored freedom; armies were easily turned against the populace, but navies that couldn’t “extend coercive force inland” presented “no menace to the liberties of a people.”⁷⁷ Mahan was an early proponent of the idea that democracies made better choices, over the long run, than autocracies, even as he worried that societies that honored “the freedom and rights of the individual” faced a growing danger from those that practiced “the subordination of the individual to the state.”⁷⁸ And if Mahan was an unrepentant nationalist, his solution to the intensifying rivalries of his era was a new level of international cooperation to keep Eurasia safe for the world.

That strategy started to coalesce in The Problem of Asia, a book published in 1900. The world’s largest continent, Mahan posited, was really three distinct regions: a northern zone (Russia and northern China) where cold weather and land power predominated; a southern zone (Egypt, the Arabian Peninsula, South and Southeast Asia) with warm weather and good sea lines of communication; and a “debated and debatable” zone (the Near East, Persia, Central Asia, central China) between. That zone was “debated” because it was a political disaster, populated by a decaying China and other feeble states. Strength would prey on weakness; a hulking Russia would try to blast through en route to warmer waters and longer coastlines. The “vast, uninterrupted mass of the Russian Empire” would then have hegemony from the Levant to the Pacific; it would possess a path to the world’s oceans with all the resulting influence. “Her tendency necessarily must be to advance,” Mahan wrote, “and it is already sufficiently pronounced to be suggestive of ultimate aims.”⁷⁹

Repelling this bid would require the grandest alliance humanity had seen. A coalition of powers around the Eurasian periphery and beyond must throttle Russia’s effort to control Asian markets and trade, to deny it the wealth that would underwrite geopolitical supremacy. That alliance must also exert steady pressure on Asia’s maritime flanks—the Mediterranean, the Indian and Pacific Oceans, even China’s great rivers—as a way of supporting local, land-based resistance to Russian advances. “The land power will try to reach the sea and utilize it for its own ends,” Mahan stated, “while the sea power must obtain support on land, through the motives it can bring to bear upon the inhabitants.”⁸⁰ Controlling the waters around Eurasia, Mahan believed, was the key to denying a dangerous hegemony there.

The Russian threat faded after 1905, but the basic problem did not. Japan was playing the Mahanian game; it had thrashed Russia at sea on the way to expanding its continental empire. If Tokyo ran the table in the Far East, it might turn its attention to the open Pacific. “Should war with Japan come before the Panama Canal is finished,” warned Mahan, “the Philippines and Hawaii might fall before we could get there.”⁸¹

Mahan was also eyeing Germany. Berlin “was likely to give us something to think about seriously on this side of the water” if it ever got a free hand in Europe, he had written in 1897.⁸² Britain might currently “hold Germany . . . in check,” he later explained, but should Britain falter, “the world would again see a predominant fleet backed by a predominant army,” in the hands of a German state that had not sated itself with colonies—and was thus all the hungrier for them.⁸³

So how should America respond? By going global in its statecraft. The Monroe Doctrine was no longer enough; Washington must practice a forward defense in overseas regions. Its objective, Mahan wrote, “should be political and military equipoise, not predominance.”⁸⁴ The United States could no more tolerate a Russia, or Japan, that overawed the eastern half of Eurasia than it could tolerate a Germany that overawed the western half: A hostile hegemony in either place would turn the adjoining oceans into vectors for insecurity. Official Washington was starting to agree. In 1899, the Open Door Note announced U.S. opposition to any power that would seek to dominate China economically or politically. What all this implied, for Mahan, was that America’s geopolitical future lay in alignment with British power.

Both countries needed the great maritime highway to remain open to their commerce. Both countries had a vital interest in preserving a world not fatally unbalanced by the aggregation of despotic power at its core. The two great ocean-going democracies must therefore work together to police the seas and sustain a global system in which their shared traditions of liberty could thrive. Once Americans appreciated their “duties to the world at large,” Mahan asserted, “we shall stretch out our hands to Great Britain, realizing that in unity of heart among the English-speaking races lies the best hope of humanity in the doubtful days ahead.”⁸⁵

Mahan’s analysis wasn’t always perfect. He was downright dogmatic in arguing that the “massed fleet of line-of-battle ships” was the only true form of sea power.⁸⁶ Critics in continental Europe rejoined that commerce raiding could choke off an enemy’s trade without requiring a climactic engagement of battleships; German submarines proved the point by nearly starving Britain into submission in World War I.⁸⁷ Mahan’s history was also sometimes slipshod; a great fleet may have saved Britain from Napoleonic invasion, but the master of Europe was ultimately beaten on land. Sea power alone was never enough, Mahan’s rival, the British naval strategist Julian Corbett, pointed out. “Since men live upon the land and not upon the sea,” wars were typically decided “by what your army can do against your enemy’s territory” or by “fear of what the fleet makes it possible for your army to do.”⁸⁸ Corbett was onto something. Winning global wars in the coming century would require coordinated operations in multiple domains.

What Mahan grasped, though, was that struggles for primacy in Eurasia would be profoundly influenced by struggles for control of its adjoining oceans. Moreover, the divergence between Mahan and Corbett obscured the convergence between their nations. Mahan was building an American school of strategy rooted in a doctrine of hegemonic denial. He was also laying the intellectual groundwork for an alliance that would have seemed improbable in the nineteenth century—and would repeatedly save the day in the twentieth.

Mahan was ahead of his countrymen in foreseeing an Anglo-American global order. He was also a forerunner of a larger, more professional community of strategists in the United States. Mahan was a self-trained scholar who used history, geography, and other subjects to divine the proper uses of U.S. power.⁸⁹ This was the goal of an entire academic discipline, strategic studies, that emerged in the first half of the twentieth century as America’s influence grew—and the world repeatedly collapsed around it. It took serial breakdowns of international order for America to build up the intellectual sinews of a superpower. At the heart of that endeavor was the question of what new technologies and new forms of tyranny meant for the world.⁹⁰

The study of international order is often a response to its absence; the study of strategy flourishes after its failure. In the transatlantic community, the modern academic field of international relations arose in response to World War I and the abortive peace that followed. Writers such as the British diplomat-turned-scholar E. H. Carr produced books that purported to offer a new, scientific approach to global affairs. Think tanks and graduate schools of international studies popped up to educate the elites of today and tomorrow. And amid a new “epidemic of world lawlessness,” as Franklin Roosevelt called it in 1937, there arose a new discipline dedicated to seeking security despite surging global chaos.⁹¹

Strategic studies married brains and money: It linked institutions of higher learning, such as Yale and the Institute for Advanced Study in Princeton, to philanthropies endowed by the likes of Rockefeller and Carnegie. It was a composite discipline, blending geography, history, economics, and political science; it brought the study of military issues into America’s civilian institutions.⁹² As violence engulfed Europe and Asia, the field’s leading scholars pondered what it would take for democracies to survive when their existence seemed threatened as never before. Totalitarian states were exerting “relentless pressure,” wrote IAS scholar Edward Mead Earle. It seemed doubtful that “the cherished heritage of Anglo-Saxon political freedom can be maintained in a world so thoroughly dominated by war.”⁹³

Technology and ideology had created a fundamentally new situation, Earle wrote in 1941. “The speed, range, and destructiveness of modern aircraft—particularly the bomber—have revolutionized warfare.” Meanwhile, all-powerful states were waging all-consuming conflict. “Total war is not new,” he acknowledged. “What is new is its terrifying potentialities when waged by a totalitarian government of imagination and daring, motivated by boundless ambition and fanatical nationalism, and possessed of all the technical resources of modern science and industry.”⁹⁴ Democracies needed their intellectuals, no less than their soldiers, to answer the call to arms.

Earle practiced what he preached. His weekly seminar at the IAS helped birth some of the field’s defining works, such as Bernard Brodie’s A Layman’s Guide to Naval Strategy. Earle spearheaded the writing of Makers of Modern Strategy: Military Thought from Machiavelli to Hitler, a pathbreaking book that enlisted nearly twenty scholars—including refugees from Hitler’s Europe—to educate Americans in military realities.⁹⁵ During World War II, Earle put his mind at the disposal of the Office of Strategic Services and the Allied bombing campaign; he wrote directly to President Roosevelt on how to fight Japan in the Pacific.⁹⁶ Earle’s ultimate ambition was to produce a “unified concept of Grand Strategy”—an integrated, comprehensive approach to securing America’s interests in war and peace.⁹⁷ Yet the person who came closest to doing so was Earle’s rival for primacy in the strategic studies pantheon: Nicholas Spykman.

Spykman made his reputation as founding director of Yale’s Institute for International Studies—a body created, in 1935, partly because the university’s students were overwhelmingly isolationist.⁹⁸ Born in Amsterdam and having worked as a journalist in the Middle East and Asia, Spykman was no provincial. “The murder of an Austrian Archduke brought a million soldiers to Europe, and the failure of an Austrian credit institution closed all the banks in the United States,” he commented; the world was interested in America, even if America was not interested in the world.⁹⁹ Having begun his academic career as a sociologist studying the centrality of power in domestic society, Spykman would refocus, amid the collapse of international society, on the centrality of power in global affairs.

Power, indeed, was Spykman’s obsession—which makes sense, given that he wrote at a time when the most ruthless countries were running roughshod over their neighbors. The world, Spykman explained in a series of influential writings, was “a society without a central authority”—there was no police department to call when order broke down. States, then, had no choice but to seek power at one another’s expense. Talk about the brotherhood of man was empty piety; morality would be tossed aside when it clashed with the quest for security. In an anarchic world, “states can survive only by constant devotion to power politics.”¹⁰⁰ And of the factors that shaped the struggle for power, Spykman argued, geography “is the most fundamentally conditioning . . . because it is the most permanent. Ministers come and ministers go, even dictators die, but mountain ranges stand unperturbed.”¹⁰¹

America’s geography had long made it “the most favored state in the world.”¹⁰² Its temperate climate, enormous size, abundant resources, and dense network of internal waterways had propelled it to economic primacy. Its comparatively benign surroundings—oceans and weak or friendly neighbors—allowed it to dominate its neighborhood with “power to spare for activities outside the New World.”¹⁰³ Now, however, technology was redefining distance; hostile states with modern air power could reach out and touch their rivals in devastating ways. If the railway preoccupied Mackinder, and the steamship transfixed Mahan, the shadow of the long-range bomber informed Spykman’s seminal works during World War II.

“The world is again in flames,” Spykman wrote in America’s Strategy in World Politics, a national bestseller released in 1942. “Advanced technology has created bigger and better engines for mass murder; devastation and destruction is again the ultimate purpose to which the energy of nations is being geared.”¹⁰⁴ Written after the fall of France had rocked the European equilibrium, the book was an urgent inquiry into whether the United States could preserve “an independent national life within the Western Hemisphere” if the Axis powers were able to “crush all resistance in the Old World.”¹⁰⁵ The answer, for Spykman, was no. Mackinder had asserted that a Eurasian hegemon would threaten democracies everywhere. Spykman set out, in nearly 500 pages of careful analysis, to prove the point beyond doubt.

There was nothing limited about the Axis design, he argued. Germany aimed to conquer “the European land mass from the North Sea to the Ural Mountains.” Tokyo sought “hegemony over the Western Pacific rimland from Siberia to Tasmania.” If they succeeded, the Western Hemisphere would be “surrounded by two gigantic empires controlling huge war potentials.” America’s position between two hostile continents would become a deadly trap, as Axis air power and sea power squeezed the New World from both sides. For isolationists who pointed out, correctly, that Hitler had never said he planned to invade America, Spykman had an answer: any country ambitious and brutal enough to conquer half the world would not long tolerate the existence of a powerful enemy in the other half. “There is nothing in the history of international relations or in the nature of power politics,” he wrote, to suggest that once Eurasian hegemony was achieved, “the struggle for power would automatically cease.”¹⁰⁶

Yet Spykman made a sophisticated case for intervention. He acknowledged that something like “continental defense,” a strategy based on protecting only the Western Hemisphere, was viable for a while. Even against a hostile Eurasia, a fully mobilized United States could control strategic islands in the Atlantic and the Pacific; it could harass approaching invasion fleets with naval forces and land-based air power; a massive army could defend the country’s coasts. It was impossible, former president Herbert Hoover declared, for Germany to “attack 130,000,000 people 3,000 miles overseas, who have a capacity of 10,000,000 soldiers and 25,000 aircraft.”¹⁰⁷ The problem was that this strategy had a shelf life, because the United States couldn’t actually hold all of the Western Hemisphere.

The Southern Cone—where most of South America’s population, agriculture, and resources were located—was separated from the rest of that continent by mountains and jungles. Thanks to the bulge of Brazil, it was farther by sea from New York than from France; it was beyond the reach of even America’s most formidable bombers. So as the Axis powers used their air and naval forces to control the Atlantic and Pacific sea lanes, America would lose its grip on events below the Amazon. It would have to make a “last stand” in a more confined “quarter-sphere” encompassing most of North America, the Caribbean, and South America above the bulge.¹⁰⁸ That quarter-sphere was fatally vulnerable to strangulation and eventual destruction.

Here Spykman showed himself to be a grand strategist, because his argument involved economic and political factors as much as military ones. In 1945, economist Albert Hirschman would publish a trenchant book, National Power and the Structure of Foreign Trade, showing how totalitarian states used predatory trade tactics to pull smaller countries into their grasp. An up-to-date version of Machiavelli, Hirschman wrote, would include “extensive new sections” on “quotas, exchange controls, capital investment, and other instruments of economic warfare.”¹⁰⁹ Spykman was ahead of him, showing how Germany would wield Eurasia’s resources, trade, and capital to force South American countries into economic and political subservience. The Axis nations would simultaneously use propaganda, subversion, and ideological warfare to bring proxy forces to power. They would gradually turn South America into a hostile redoubt, while using blockades and embargoes to cut the United States off from tin, copper, and other vital materials. “Military warfare in all periods of history has been accompanied by political action,” Spykman wrote. Once America was so weakened that it could not defend the quarter-sphere, its enemies would close in for the kill.¹¹⁰

The implications were stark: indifference to the fate of distant countries could jeopardize the survival of America itself. The world was not divided into “water-tight compartments,” Spykman wrote. “Only statesmen who can do their political and strategic thinking in terms of a round earth and a three-dimensional warfare can save their countries from being outmaneuvered on distant flanks.” The United States must defeat the Axis powers before they gained unstoppable momentum—and then undertake a permanent campaign to keep Eurasia fragmented. Washington might even have to revive a defeated Germany to prevent the Soviet Union from taking its place: “A Russian state from the Urals to the North Sea can be no great improvement over a German state from the North Sea to the Urals.”¹¹¹ Geopolitics was not a task for the morally squeamish or sentimental. The enduring requirements of U.S. security were preponderant power in the Western Hemisphere and a balance of power everywhere else.

But which parts of Eurasia mattered most? This was a long-running point of contention. Mackinder had imagined a peerless land power using the Pivot area as a springboard. Mahan saw sea power as real power and focused on the struggle for the Pacific and Indian Oceans. Spykman offered his own twist, in a book, The Geography of the Peace, that appeared after his life was cut short by illness, in 1943. The real danger, he suggested, came not from a Pivot covered with permafrost. It came from the Eurasian Rimland, that “vast buffer zone of conflict” where sea power and land power met head-on.¹¹²

“Siberia is practically empty of people while the Rimland sections in Europe, India, and China are crowded,” Spykman wrote. “History tells us that it is in these latter regions rather than in the former that great civilizations and world-powerful states have existed.” These areas, roughly equivalent to Mackinder’s Inner Crescent, were home to Eurasia’s most economically dynamic, densely populated countries. They were adjacent to its vital “inner seas”—bodies such as the Mediterranean, South China Sea, and East China Sea. These waterways and not the open oceans carried most of the world’s seaborne trade, Spykman argued; they controlled maritime access to Eurasia itself. It was no coincidence that two world wars had seen Germany and Japan, two Rimland powers, seek mastery of the industry-rich peripheries of Eurasia, while also reaching into the adjoining waters. Nor would Spykman have found it odd that today’s U.S.–China rivalry is playing out primarily in the interior waterways—the East China Sea, the South China Sea, the Taiwan Strait—of the most economically important region.

Spykman’s most famous contribution was thus a partial inversion of Mackinder. The Mackinder Doctrine was that control of the Heartland led to control of the world. The Spykman Corollary was that “who controls the Rimland rules Eurasia; who rules Eurasia controls the destinies of the world.”¹¹³

This point had implications for military strategy and the long-running land power–sea power debate. Since the Rimland was accessible by both water and land, fights for dominance there would not be straight-up battles between maritime powers and continental powers. They would be clashes of an amphibious nature. Offshore powers needed sea and air control just to reach Eurasia, but they also needed powerful armies on land to beat down their enemies there. “Sea and air power,” wrote Spykman, echoing Corbett, were “the instrumentalities to achieve decisions on land.”¹¹⁴

Spykman wasn’t for everyone. His unrelenting focus on power was dark; his apparent amorality could be striking. Spykman’s work, wrote Earle in one sour review, was sometimes savaged as “a primer for a new American Prussianism.” Earle didn’t go that far, but he was appalled by Spykman’s suggestion that the best guarantee of American security was a Eurasia forever mired in division. “At the end of the war the only choice we may face is that between a more stable organization and the end of all organization, between some sort of order and complete anarchy,” he wrote. “The balance of power may well land us all in a crematory.”¹¹⁵

Yet Spykman was right that Washington would eventually use a de-Nazified Germany to contain Moscow. His wartime writings were visionary in other ways as well. Spykman provided the most nuanced case for why, exactly, a consolidated Eurasia could prove so deadly for even a strong and distant America—an argument that resonated with U.S. policymakers through World War II and the Cold War. He illustrated how totalitarian states were practicing a totalizing approach to warfare. When George Kennan, during the early Cold War, warned that such states would employ “varieties of skullduggery . . . as unlimited as human ingenuity itself, and just about as unpleasant,” he was learning from Spykman.¹¹⁶ Even the devil’s morality Spykman preached wasn’t quite what it appeared.

“All civilized life rests . . . in the last instance on power,” he wrote; any society that ignored that reality was destined for oblivion.¹¹⁷ The fundamental question of strategic studies was how democracies could maintain their way of life in a terrifying age of global war. Spykman’s answer was, by playing geopolitics remorselessly—and persistently—enough to salvage a world in which liberal institutions might endure.

Whatever their differences, Mackinder, Mahan, and Spykman were members of a democratic school of geopolitics. Their goal was to craft strategies that would allow free nations to flourish. Yet there was also an authoritarian school of geopolitics, which put the discipline to very different ends. For these thinkers, Mackinder’s vision—a world with a tyrannical Eurasia at its center—was not a nightmare to be averted. It was a dream to be achieved.

Maritime powers, writes historian S. C. M. Paine, have the option of basing their security on economic prosperity, which allows them to pursue positive-sum strategies rooted in trade and cooperation. Continental powers exist in cramped, cutthroat conditions, where the surest route to safety may be vivisecting their neighbors. For similar reasons, democracy was historically more likely to take root in insular (or effectively insular) countries that didn’t need large armies than in continental states that did. Oceans promoted economic and political openness; cramped landmasses were laboratories for aggression and tyranny.¹¹⁸ So it makes sense that the democratic school of geopolitics was an Anglo-American creation, while the authoritarian school arose in continental Europe.

This latter school was, in some respects, the original: the term “geopolitics” was first associated with Swedish intellectual Rudolf Kjellén and German geographer Friedrich Ratzel in the late nineteenth and early twentieth centuries. These thinkers were deeply influenced by social Darwinism; they saw nations as living organisms that must expand or die, and they defined nationhood in racial terms. The resulting form of geopolitics, writes one scholar, was “vindictive and expansionist.” It prioritized the coercive quest for lebensraum, or “living space,” a term Ratzel coined; it blossomed in countries, such as imperial Germany, where expansionist visions and illiberal values went hand in hand.¹¹⁹ Geopolitics tempered by democracy was stark but rarely evil. Geopolitics with an autocratic bent was poison, pure and simple.

The epitome of this approach was the “Munich school,” led by General Karl Haushofer. Haushofer had been an artillery commander in World War I. After Germany’s defeat, he participated in right-wing paramilitary organizations while starting a new career as an academic. By the late 1920s, Haushofer’s magazine on geopolitics was selling up to 500,000 copies annually; monthly radio broadcasts amplified his message.¹²⁰ The general was more prolific than penetrating; he wrote some forty books and 400 articles, many of which were rambling, repetitive, and mutually contradictory. His message, though, was well matched to a country that felt humiliated by the Versailles settlement—and to a Nazi leadership seeking intellectual legitimacy for revolutionary designs.

For Haushofer, geopolitics was expansion. Germany, thanks to its “ordeal of ruthless mutilation” after World War I, had been pinned into intolerable confines. Its only response was to “emerge out of the narrowness of her present living space into the freedom of the world.” Germany must carve out an autarkic imperium encompassing Europe and Africa. Other oppressed, have-not countries—especially the Soviet Union and Japan—would do likewise across the remainder of Eurasia and the Pacific. Only by consolidating such “pan-regions” could the ravenous revisionist states overmatch their enemies, namely the United Kingdom; only by working together could they prevent Britain from playing divide-and-conquer. “Never again,” wrote Haushofer in 1939, should Germany and Russia let “ideological conflicts” set them against each other. The goal of Haushofer’s geopolitics was a Eurasia ruled by an autocratic alliance.¹²¹

There was no chance, and no pretension, this could be accomplished without murder and mayhem. The world, wrote Haushofer, needed “a general political clearing up, a redistribution of power.” The young Eastern European countries lying athwart Germany’s path were “state fragments” that “have no longer a right to exist.”¹²² Haushofer would endorse German aggression in the late 1930s and early 1940s, even as it became clear that this involved killing millions in the “living space” Berlin desired.

Haushofer’s writings seem like an upside-down version of Mackinder, because that’s exactly what they were. Mackinder had worried that a continental hegemon could outpace Great Britain; Haushofer wanted to accomplish exactly that. Haushofer carefully read and liberally borrowed from Mackinder’s works; he even explicitly credited the idea of a Nazi–Soviet alliance to Mackinder, who as early as 1904 had worried that such a combination might be the ruin of the world. “Where does world history say that one may not learn from the enemy?” Haushofer crowed in 1939. “Russia and Germany both lost the [last] war because they fought on opposite sides. It took . . . a much longer time than Sir Halford Mackinder had expected, for the Germans and Russians to find that out.”¹²³ Mackinder, it turned out, was the “academic scribbler” influencing Haushofer, who influenced none other than Adolf Hitler.

To be sure, Haushofer’s influence on Hitler has sometimes been exaggerated. After World War II, U.S. war crimes prosecutors alleged that the former was the latter’s “intellectual godfather,” with Hitler “only a symbol and a rabble-rousing mouthpiece.”¹²⁴ During the war, the OSS described Haushofer as the man who had “transformed the study of Geopolitics . . . into an instrument of German aggression on a world scale.”¹²⁵ In reality, Haushofer’s relationship to the Nazi regime was more ambivalent, in part because he was an old-school German conservative rather than a radical National Socialist, and in part because his wife was half-Jewish. Haushofer had misgivings about Hitler’s eventual decision to attack the Soviet Union; his son would ultimately join the anti-Hitler resistance and pay for that decision with his life. Even so, Haushofer was present at the creation of Nazi geopolitics.¹²⁶

The connection was Rudolf Hess, Haushofer’s former aide and Hitler’s prison-mate after the failed Beer Hall Putsch of 1923. Haushofer introduced Hitler to his theories of geopolitics during visits to Landsberg prison. “It is a pleasure, after a full soldier’s life, to function as an old academic,” he wrote, “even if the young eagles remain behind bars for a while.”¹²⁷ As the Nazis gained influence, Haushofer maintained close contact with Hess, who became Deputy Führer; he saw Hitler as the vessel through which his intellectual rantings could become reality. Haushofer’s son, Albrecht, described his father’s views: “Whether we like it or not, they are now in the saddle; we cannot simply throw them out; thus we have the damned duty and obligation to put our shoulder to the wheel so that they will quickly lose their childhood ailments and learn to accept the right teachings.”¹²⁸

Those teachings left a mark. Haushofer may not have written Hitler’s infamous treatise, Mein Kampf, but he certainly influenced it. Central arguments—the supposed illogic of Germany’s interwar borders, the imperative to find living space in the east, the importance of eliminating European rivals—were “pure Haushofer,” historian Holger Herwig writes.¹²⁹ “Only an adequately large space on this earth assures a nation of freedom of existence,” Hitler asserted in one passage. “Hence, the German nation can defend its future only as a world power.”¹³⁰ Hitler’s later advocacy of a continental empire as an answer to British and American power also echoed his mentor’s ideas. As the geopolitical theorist Robert Strausz-Hupé observed, “Hitler found in Geopolitik a coherent explanation as to how world powers had developed in the past and how Germany could assume her place in the historic procession of great states.”¹³¹ Haushofer cheered loudly from the sidelines as annexations, invasions, and atrocities followed. The Führer, he proclaimed, was “a Charlemagne,” a practitioner of “geopolitical mastery.”¹³²

It didn’t end any better for the old academic than for the young eagle. By 1940, Haushofer realized that he had encouraged forces he could hardly control. Karl and Albrecht quietly sent out feelers to acquaintances in England about ending the war Hitler had started.¹³³ Those failed, and the Haushofers lost influence when Hess fled Germany for Scotland on a one-man peace mission in 1941. The father quietly grew more alienated; the son, having conspired to assassinate Hitler in 1944, was executed by the Führer’s henchmen as defeat impended. Karl Haushofer then killed himself while under investigation for war crimes by the Allies. “I want to forget and to be forgotten,” his suicide note read.¹³⁴

Haushofer wasn’t quickly forgotten; his legacy was to tar the very idea of geopolitics and the reputation of its foremost practitioners. Mackinder, alleged one writer in 1947, was “the man behind the man behind Hitler.” He added, not as a compliment, that “there is hardly a man or woman or child in these times whose past and future is not in some degree touched by the ideas for which Mackinder stood.”¹³⁵ This was terribly unfair to Mackinder, who abhorred Hitler and all he represented. But it was true that there were darker elements to geopolitics—the emphasis on power and the permanency of struggle, the willingness to make moral compromises—that aggressive autocrats would not hesitate to weaponize.

That, too, would become a venerable tradition of the Eurasian century. Even today, when tyrants and their acolytes use geopolitical principles to justify radical expansion, they are following in Haushofer’s tradition—and they are, perversely, channeling Mackinder as well.

Consider Aleksandr Dugin, an intellectual who made a name for himself as an ideologue of Russian resurrection. Like Haushofer, he was an intellectual disciple of Mackinder. After the collapse of the Soviet Union, Dugin used Mackinder’s theories to explain how a new empire could arise from the ashes of the old.

Russia, Dugin argued, was existentially threatened by an American-led “Atlanticist” coalition seeking to implant its degraded liberal values everywhere. Moscow’s best answer was to restore a “great-continental Eurasian future for Russia with our own hands.” By reasserting control of the former Soviet republics, by forging alliances with other dissatisfied states, Russia could build a bloc formidable enough to frustrate a superpower. “The heartland of Russia” was the “staging area of a new anti-bourgeois, anti-American revolution,” he wrote. “The Eurasian Empire will be constructed on the fundamental principle of the common enemy: the rejection of Atlanticism, strategic control of the USA, and the refusal to allow liberal values to dominate us.”¹³⁶

Beginning in the 1990s, Dugin became hugely influential within the Russian military establishment, where his geopolitical tracts were required reading. He seemed also a bit of a madman; after his daughter died a fiery death in 2022, in a car bombing presumably conducted by Ukrainian intelligence assets and meant for Dugin himself, he claimed that “our empire” was one of her first phrases as a child.¹³⁷ Few would say the same of Andrew Marshall, the quietly brilliant Pentagon strategist who had a reputation for looking farther into the future than his peers. Yet in 2002, Marshall tapped into the same body of thought that animated Dugin. A rising China could soon test the existing order, he warned. Washington must brace “for a long term competition . . . for influence and position within the Eurasian continent and the Pacific Rimland.”¹³⁸

The great geopolitics debate of Mackinder’s era cast a long shadow; a century later, both enemies and friends of a liberal world order were still using it as a guide.¹³⁹ Mackinder and his contemporaries achieved a certain immortality. Their writings shaped the hopes and fears of statesmen through the generations that followed.

Each of these thinkers contributed something essential. Mahan was a prophet of the Anglo-American alliance, because he understood the role that sea control would play in struggles for dominance on land. Spykman showed that the Rimland could be just as menacing as the Heartland, and that geographic isolation was no guarantee of safety in a globalized age. Haushofer revealed how geopolitics, when divorced from democratic scruples, could be a recipe for iniquity. But above all, it was Mackinder’s era. Eurasia became a geopolitical hothouse due to dynamics he identified.

The closing-off of strategic safety valves thrust the great powers against one another. The march of technology shrank Eurasia’s epic geography. The emergence of totalitarian states with industrial economies fueled aggression and conquest. All this served to pit a series of potential Eurasian hegemons against liberal superpowers whose freedom and security depended on dashing those designs. The brutal clarity of Mackinder’s thesis was that the stars were aligning for persistent, high-stakes struggle over Eurasia and the larger world. The brutal history of the Eurasian century would show how right he was.