The United States entered the war in a grinding economic depression and exited at the beginning of an unparalleled economic boom. The war had been won, the United States was stronger than ever, and Americans looked forward to a prosperous future. And yet new problems loomed. Stalin’s Soviet Union and the proliferation of nuclear weapons would disrupt postwar dreams of global harmony. Much-contested zones of postwar occupation would set the stage for the Cold War, as the Soviet Bloc and the democracies of the West vied for ideological and military supremacy.

Meanwhile, Americans who had fought a war for global democracy would find that very democracy eradicated around the world in reestablished colonial regimes and at home in multiple examples of segregation and injustice. The substantial economic gains made by women and racial minorities during the war would prove to be fragile, and in many cases, temporary. The war had unleashed powerful cultural, political, and economic forces that would reshape the United States as well as the broader world order.

Figure 1. An array of flags in front of the United Nations building. Among the many represented are the flags of the United States, the United Kingdom, and Ukraine.

In this section, we learned that World War II radically reconfigured the international political balance. New powers emerged and some established powers were revitalized, while at least two aggressively expansionist nations were militarily defeated and would face difficult periods of reconstruction in the second half of the twentieth century. A key element in this process of postwar readjustment would be the multilateral diplomacy enabled by the United Nations, an imperfect but essential resource for maintaining peace and providing an open forum for negotiation, tolerance, and mutual recognition.