The Boer War of 1899–1902 dramatized the high cost of policing the empire and served as both harbinger and accelerant of British decline. Perceptions grew of an ever-widening gap between Britain’s strategic commitments and the resources available to maintain them. Also, the rest of the world became less and less willing to submit to British influence and power. The empire’s strategic isolation was captured in the plaintive words of Spenser Wilkinson, military correspondent for the Times: “We have no friends, and no nation loves us.”

Imperially overstretched and confronting a deteriorating strategic environment, London was forced to adjust its grand strategy and jettison its nineteenth-century policy of “splendid isolation” from entanglements with other countries. Another consideration was the rising threat of Germany, growing in economic dynamism, military might and population. By 1900, Germany had passed Britain in economic power and was beginning to threaten London’s naval supremacy in its home waters by building a large, modern and powerful battle fleet. To concentrate its forces against the German danger, Britain allied with Japan and employed Tokyo to contain German and Russian expansionism in East Asia. It also removed America as a potential rival by ceding to Washington supremacy over the Americas and the Caribbean. Finally, it settled its differences with France and Russia, then formed fateful de facto alliances with each against Germany.

World War I marked the end of Pax Britannica—and the beginning of the end of Europe’s geopolitical dominance. The key event was American entry into the war. It was Woodrow Wilson who called the power of the New World “into existence to redress the balance of the Old” (in the words of the early nineteenth-century British statesman George Canning). American economic and military power was crucial in securing Germany’s defeat. Wilson took the United States to war in 1917 with the intent of using American power to impose his vision of international order on both the Germans and the Allies. The peace treaties that ended World War I—the “Versailles system”—proved to be flawed, however. Wilson could not persuade his own countrymen to join his cherished League of Nations, and European realpolitik prevailed over his vision of the postwar order.

Although the historical wisdom is that America retreated into isolationism following Wilson’s second term and Warren Harding’s return to “normalcy,” that is not true. The United States convened the Washington Naval Conference and helped foster the Washington naval treaties, which averted a U.S. naval arms race with Britain and Japan and dampened prospects for increased great-power competition over influence in China. America also played a key role in trying to restore economic, and hence political, stability in war-ravaged Europe. It promoted Germany’s economic reconstruction and political reintegration into Europe through the Dawes and Young plans that addressed the troublesome issue of German reparations. The aim was to help get Europe back on its feet so it could once again become a vibrant market for American goods.

Then came the Great Depression. In both Europe and Asia, the economic cataclysm had profound geopolitical consequences. As E. H. Carr brilliantly detailed in his classic work The Twenty Years’ Crisis, 1919–1939, the Versailles system cracked because of the growing gap between the order it represented and the actual distribution of power in Europe. Even during the 1920s, Germany’s latent power raised the prospect that eventually Berlin would renew its bid for continental hegemony. When Adolf Hitler assumed the chancellorship in 1933, he unleashed Germany’s military power, suppressed during the 1920s, and ultimately France and Britain lacked the material capacity to enforce the postwar settlement. The Depression also exacerbated deep social, class and ideological cleavages that roiled domestic politics throughout Europe.

In East Asia, the Depression served to discredit the liberal foreign and economic policies that Japan had pursued during the 1920s. The expansionist elements of the Japanese army gained sway in Tokyo and pushed their country into military adventurism in Manchuria. In response to the economic dislocation, all great powers, including the United States, abandoned international economic openness and free trade in favor of economic nationalism, protectionism and mercantilism.

The crisis of the 1930s culminated in what historian John Lukacs called “the last European war.” But it didn’t remain a European war. Germany’s defeat could be secured only with American military and economic power and the heroic exertions of the Soviet Union. Meanwhile, the war quickly spread to the Pacific, where Western colonial redoubts had come under intense military pressure from Japan.

World War II reshaped international politics in three fundamental ways. First, it resulted in what historian Hajo Holborn termed “the political collapse of Europe,” which brought down the final curtain on the Eurocentric epoch of international politics. Now an economically prostrate Western Europe was unable to defend itself or revive itself economically without American assistance. Second, the wartime defeats of the British, French and Dutch in Asia—particularly the humiliating 1942 British capitulation in Singapore—shattered the myth of European invincibility and thus set in motion a rising nationalist tide that within two decades would result in the liquidation of Europe’s colonies in Asia. This laid the foundation for Asia’s economic rise that began gathering momentum in the 1970s. Finally, the war created the geopolitical and economic conditions that enabled the United States to construct the postwar international order and establish itself as the world’s dominant power, first in the bipolar era of competition with the Soviet Union and later as the globe’s sole superpower following the 1991 Soviet collapse.

Thus do we see the emergence of the new world order of 1945, which now represents the Old Order that is under its own global strains. But we also see the long, agonizing death of Pax Britannica, which had maintained relative global stability for a century before succumbing to the fires of the two world wars and the Great Depression. This tells us that periods of global transition can be chaotic, unpredictable, long and bloody. Whether the current transitional phase will unfold with greater smoothness and calm is an open question—and one of the great imponderables facing the world today.

AS THE United States emerged as the world’s leading power, it sought to establish its postwar dominance in the three regions deemed most important to its interests: Western Europe, East Asia and the Middle East/Persian Gulf. It also fostered an open international-trading regime and assumed the role of the global financial system’s manager, much as Britain had done in the nineteenth century. The 1944 Bretton Woods agreement established the dollar as the international reserve currency. The World Bank, International Monetary Fund, and the General Agreement on Tariffs and Trade fostered international commerce. The United Nations was created, and a network of American-led alliances established, most notably NATO.

It is tempting to look back on the Cold War years as a time of heroic American initiatives. After all, geopolitically, Washington accomplished a remarkable double play: while avoiding great-power war, containment—as George F. Kennan foresaw in 1946—helped bring about the eventual implosion of the Soviet Union from its own internal contradictions. In Europe, American power resolved the German problem, paved the way for Franco-German reconciliation and was the springboard for Western Europe’s economic integration. In Asia, the United States helped rebuild a stable and democratic Japan from the ashes of its World War II defeat. For the trilateral world of Pax Americana—centered on the United States, Western Europe and Japan—the twenty-five years following World War II marked an era of unprecedented peace and prosperity. These were remarkable accomplishments and are justly celebrated as such. Nevertheless, it is far from clear that the reality of the Cold War era measures up to the nostalgic glow in which it has been bathed. Different policies might have brought about the Cold War’s end but at a much less expensive price for the United States.

The Cold War was costly in treasure and in blood (the most obvious examples being the wars in Korea and Vietnam). America bears significant responsibility for heightening postwar tensions with the Soviet Union and transforming what ought to have been a traditional great-power rivalry based on mutual recognition of spheres of influence into the intense ideological rivalry it became. During the Cold War, U.S. leaders engaged in threat inflation and overhyped Soviet power. Some leading policy makers and commentators at the time—notably Kennan and prominent journalist Walter Lippmann—warned against the increasingly global and militarized nature of America’s containment strategy, fearing that the United States would become overextended if it attempted to parry Soviet or communist probes everywhere. President Dwight Eisenhower also was concerned about the Cold War’s costs, the burden it imposed on the U.S. economy and the threat it posed to the very system of government that the United States was supposed to be defending. Belief in the universality of American values and ideals was at the heart of U.S. containment strategy during most of the Cold War, and the determination to vindicate its model of political, economic and social development is what caused the United States to stumble into the disastrous Vietnam War.

Image: Pullquote: Periods of global transition can be chaotic, unpredictable, long and bloody. Whether the current transitional phase will unfold with greater smoothness and calm is an open question.Essay Types: Essay