Part III: This essay is the third in our week-long series on geopolitics by Hal Brands, the Henry A. Kissinger Distinguished Professor of Global Affairs at the Johns Hopkins University and a senior fellow at the American Enterprise Institute. You can read part one here, and part two here, part four here, and part five here.

The first half of the twentieth century often seemed like a progression from one nightmare to the next. In 1918, a transatlantic alliance had strained to beat back one hegemonic challenge, only for the world to face another, of greater malevolence and brutality, two decades later. At the worst moments of the Second World War, the Axis powers dominated the Eurasian rimlands, were pushing deep into the heartland, and were menacing the island sanctuaries and oceanic supply lines keeping their enemies alive. This was the closest the world ever came to falling into a totalitarian dark age. Restoring Eurasian equilibrium — and the prospects for democratic survival — would require far greater exertions, and consume far more lives, than the First World War. 

The Second World War was, in fact, the nadir of the Eurasian century and the darkest realisation of Mackinder’s vision. The run-up to war saw the rise of totalitarian regimes that employed the resources of modern societies for aggression, enslavement, and genocide. Technological breakthroughs enabled conquest on an epic scale within Eurasia while amplifying threats to countries beyond it. Not least, the entire saga showed that the difficulties of blunting hegemonic challenges early could be severe—but that the price of rolling them back later could be even worse.

In all of these respects, the Second World War offered a costly and enduring geopolitical education. It also gave Mackinder occasion, in his later years, to offer the kernel of a strategy for preventing such a bloody catastrophe from happening again.

Breaking the balance

Mackinder had seen it coming: He warned in 1919 that the post-First World War peace might not last. That settlement had been meant to cure the international anarchy that Woodrow Wilson blamed for the conflict — to create a ‘community of power’ in place of a supposedly anachronistic balance of power. But that vision failed, ironically, because neither America nor the other beneficiaries of the post-war order were willing to use power to defend it. The Great Depression then destroyed the economic cooperation that had provided a degree of geopolitical stability in the 1920s, while also empowering radical regimes with breathtaking visions of conquest.

Hitler and his Japanese counterparts saw expansion as the only path to security and prosperity. In a fragmenting world, they believed, carving out autarkic blocs was essential to grabbing markets and resources and amassing the strength for global competition. Hitler, writes the historian Timothy Snyder, wanted to make Germany ‘unassailable’ through expansion to the East, the subjugation of European rivals, and the creation of an overseas empire. Japan sought a huge sphere of influence incorporating East Asia and the Western Pacific. The revisionist powers hoped to turn themselves into geopolitical fortresses, able to withstand pressure from — and prevail over — the guardians of the existing order.

Mackinder’s thinking loomed large here: Nazi geopoliticians drew on his thesis to argue that only Eurasian dominance could make Germany invulnerable. Hitler believed Germany must destroy its Continental rivals — while also ‘purifying’ itself and its conquered lands through genocide — to prevail in the inevitable struggle with a country that itself dominated a continent: the US. In the hands of leaders unmoored from morality, geopolitics became a formula for atrocity and aggression.

A strong, concerted response might still have kept such powers in check. But in the 1930s, there was no balancing coalition to be had. One potential anchor, the Soviet Union, was itself a radical revisionist power committed to global revolution; it would ally with Germany from 1939 to 1941. Another potential anchor, America, had interpreted the failed peace after The First World War as cause to abandon its strategic commitments in Europe, and acted as though geography might yet shield it from instability there.

The European democracies, still scarred by the First World War, were able but not willing to crush Hitler when he was weak, and willing but not able to stop him once he was strong. All of which demonstrated the difficulty of rallying a counterhegemonic coalition before the severity of the challenge had been fully revealed—and cleared the way to a piecemeal, but ultimately fundamental, revision of Eurasian order.

From 1938 to 1940, Hitler picked off enemies — Austria, Czechoslovakia, Poland, Denmark and Norway, the low countries, France—one or two at a time, until Germany and its allies reigned supreme within Europe. Between 1931 and 1941, Japan made moves in Manchuria, China proper, and Indochina; in December 1941 and early 1942, it then swept through Southeast Asia and the Pacific.

Incremental gains added up to strategic catastrophe: The Eurasian balance had been broken more quickly and fully than virtually any observer had imagined. By that point, the two regional crises had also merged into a single global crisis, as Japan and Germany — along with Italy — signed a Tripartite Pact meant to foster a worldwide ‘new order.’ ‘The era of democracy is finished,’ Yōsuke Matsuoka, Japan’s foreign minister declared. ‘Totalitarianism … will control the world.’

A deadly race

That seemed possible, in the war’s darkest days. For in dominating Europe and much of the Asia-Pacific, Germany and Japan had laid bare sobering truths about the modern world.

First, Germany’s conquests showed how technology, in shrinking distance, had facilitated aggression. Germany masterfully used airborne assaults against Denmark and Norway; it employed tanks and tactical airpower to defeat France and punch through to the Atlantic in just weeks. Similar tactics would, in 1941, bring the Balkans and huge swathes of the Soviet Union under Hitler’s control. Blitzkrieg was the operational concept that enabled a strategy of Eurasian domination; Hitler could use lightning strikes to conquer countries whose resources could be added to his own.

Second, a totalitarian Eurasia would be a moral and strategic cataclysm for the world. The extermination of the Jews, murder of captive populations, and use of slave labour showed how Hitler planned to run his empire. Japanese germ warfare, sexual and economic enslavement, and indiscriminate violence against civilians underscored how awful the new order would be. ‘The future world will be a shabby and dangerous place to live in,’ said Franklin Roosevelt in 1940, ‘if it is ruled by force in the hands of a few.’

Third, the conflict showed—not at all hypothetically—just how easily insecurity could radiate outward in a world with a totalitarian Eurasia at its core. Having overrun Europe, Germany was threatening the United Kingdom, the Middle East, and the Mediterranean. From French and Norwegian bases, German U-boats waged a Battle of the Atlantic that nearly destroyed the Old Worlds’s hopes for salvation by the New. And once Germany absorbed the fruits of conquest, it would be an economic superpower, capable of building a military with truly global reach.

When Japan used carrier-based airpower to strike Hawaii in December 1941, it confirmed that Eurasian hegemony had become a platform for global aggression. The fate of the world now hinged on a deadly race. The Axis powers, especially Germany, were rushing to consolidate control of Eurasia and prepare for global conflict with America. Washington and its allies had to defeat them before they could harness the potential of that region and turn their attention to the wider world.

It was a near-run thing. By mid-1942, Japanese power stretched from the Indian frontier to the international date line, from Manchuria to Australia’s oceanic approaches. Germany ruled Europe from France to the Caucasus; having turned on Stalin, Hitler was now threatening to crush the last resistance to German power on the Eurasian mainland. Perhaps most worrying was the prospect that the Axis powers might physically link up, through the Middle East or the Indian Ocean. That, the Dutch-American political scientist Nicholas Spykman observed, would have presented the ‘possibility of complete encirclement.’ Against ‘the unified power of the whole Eurasian landmass,’ it might be ‘impossible for us to preserve our independence and security.’

Mid-1942 turned out to be the high-water mark of the Axis, but it didn’t have to be. Had Hitler made a serious peace offer to Britain in 1940, he might have had calm in the West that would have facilitated victory in the East. Had Japan conducted a limited strike against European colonies in December 1941, while avoiding a tactically successful but strategically suicidal attack on the United States, it might have won critical time to digest its gains.

The list goes on; the ‘what if’s’ of the Second World War remind us that the outcome was hardly a given. Yet in the end, the Axis powers were crushed, thanks to several factors that went to the heart of strategy in the Eurasian century.

The crunch

One was that the cruel logic of geography, along with the cruel behaviour of the Axis powers, eventually maximised the number of enemies they faced. To be a Eurasian power is to be surrounded by potential rivals. The vastness of the totalitarian powers’ designs, when added to the brutality of their methods, turned those potential rivals into real ones.

By pursuing revolutionary ambitions with murderous zeal, Hitler made a communist Soviet Union the ally of the very capitalist powers it sought to destroy. By overrunning France and menacing Britain, he brought the one country capable of reversing his domination of Western Europe — the United States — into the fight. Japan’s expansion likewise precipitated encirclement, by provoking powers — the Soviet Union, China, the British and the Dutch, Australia and America — at every point on the compass.

These dubious achievements, in turn, forced Berlin and Tokyo to disperse their forces across vast spaces, rather than concentrating them decisively. They ultimately embroiled the Axis powers in multi-front wars against rivals whose collective strength outstripped their own.

Yet it wasn’t just the mass of that coalition that mattered; it was also the composition. In geopolitical terms, the Grand Alliance succeeded because it featured land powers that could deny Germany and Japan a free hand within Eurasia, as well as sea and airpowers that could eventually dominate the oceans around it and the skies above it.

From December 1941 onward, Washington had allies (China and the Soviet Union) within Eurasia, in addition to crucial island bases (Britain and Australia) off its shores. Roosevelt went to great lengths to keep those allies, especially Moscow, in the war, because doing so was the only way of preventing the Axis from consolidating their Continental gains and turning their full fury on the world.

The Soviet Union suffered the vast majority of Allied casualties and accounted for the vast majority of German battle deaths. Less well known, but equally essential, China faced more Japanese forces than America did in all but one year (1944) of the war. The reason the New World could save the Old was that its enemies’ attention was always divided.

Just as crucial was the air and maritime supremacy America and Britain achieved. Command of the air and seas allowed the Allies to island-hop across a hostile Pacific and eventually fight their way onto an occupied Europe. Strategic bombing permitted the Allies to sow devastation deep within hostile territory. Air and maritime dominance denied enemy forces freedom of movement on land or at sea, depriving them of the advantages interior lines generally provide.

Most critically, it was the hard-won victory in the Battle of the Atlantic that allowed America to bring its world-beating industrial might to bear, turning that ocean into what Mackinder called a ‘Midland Sea’ across which the means of victory could flow freely. ‘It is in shipping,’ Winston Churchill reminded Roosevelt, ‘and in the power to transport across the oceans … that the crunch of the whole war will be found.’ Aerial and maritime dominance held the globe-spanning Grand Alliance together, while gradually breaking its opponents apart.

Finally, this amphibious alliance flourished because it achieved a far higher level of cooperation than the Axis could. Remarkably, Japan and Germany never pursued a strategic link-up or seriously coordinated operations. Trust was in short supply between murderous autocrats; the vicious racism that pervaded the Axis didn’t help.

America and Britain, by contrast, cooperated more deeply — on strategy, military operations, intelligence, and other matters — than perhaps any two sovereign states in history. The relationship with Stalin was more problematic, but even here American supplies and Soviet manpower provided the necessary synthesis. And it is no coincidence that the term ‘grand strategy’ gained currency during the Second World War. That conflict required allied leaders, especially Roosevelt and Churchill, to systematically allocate resources across theatres, clearly prioritise among conflicting objectives, and synchronise military, diplomatic, and economic efforts — tasks that democratic leaders managed far more effectively than their totalitarian rivals.

The struggle for Eurasia, and for the world, was inherently a multilateral affair. The Allies prevailed, in great measure, because they managed to make the sum of their exertions greater than the total of the parts.

USA, here to stay

The cost was ghastly: The final truth the Second World War demonstrated was how excruciatingly expensive it could be to repair a geopolitical balance after it had been broken. The price could be measured in the 60 million lives lost during the war, the devastation of areas from one side of the world to the other, and not least in the legacy the war left behind.

In failing to thwart Hitler’s ambitions early, the democracies had forced themselves to defeat one totalitarian evil by relying on another. The Soviet Union emerged from the Second World War with its troops occupying half of Europe; it had a commanding position amid a shattered Eurasia. As American analysts wrote in 1945, ‘Russia will emerge from the present conflict as by far the strongest nation in Europe and Asia—strong enough, if the United States should stand aside, to dominate Europe and at the same time to establish her hegemony over Asia.’

Mackinder had acknowledged as much in 1943, although he hoped that the Grand Alliance would survive the war and worried mostly about a German resurgence. Yet he also offered, in his last major essay, an idea to prevent any power from achieving what Hitler had just attempted.

The basic problem before the Second World War was that the countervailing coalition had not come together until it was nearly too late. The answer was to turn the wartime alliance into an enduring transatlantic community. 

This community would consist of ‘a bridgehead in France, a moated aerodrome in Britain, and a reserve of trained manpower, agriculture and industries in the eastern United States and Canada.’ It would treat the ‘Midland Ocean’ not as a barrier but as a highway linking like-minded countries on both sides. Which meant that there must not be another postwar American retrenchment; lasting peace required ‘lasting cooperation’ among the Western democracies to ensure that any hegemonic aspirations would be checked with immediate resistance on land, in the air, and at sea.

The Second World War had, tragically, created the conditions for a third struggle for Eurasian hegemony. It also gave rise, fortunately, to the strategic concept that would allow the West to prevail without fighting a third global war.