With Japan’s surrender in August 1945, Americans besieged the government for the return of their loved ones. They were eager to dismantle the large military establishment and expected the United States and its allies, working with the United Nations, to cooperate in the management of international peace. Postwar realities quickly dashed these hopes. The wartime alliance forged by the United States, Great Britain, and the Soviet Union crumbled, giving birth to a Cold War. The United States began to develop the means for containing the spread of Soviet power around the globe, including a military buildup and an enormous aid program for Europe, known as the Marshall Plan.