Yalta Conference, the last meeting of the World War II “Big Three,” held February 7-12, 1945, at Yalta, in the Soviet Union. President Franklin D. Roosevelt of the United States, Prime Minister Winston Churchill of Great Britain, and Premier Joseph Stalin of the Soviet Union discussed strategy for ending the war and made plans for the postwar world. They pledged to destroy German militarism and the Nazi party. Upon surrender, Germany would be divided into American, British, Soviet, and French occupation zones. An Allied Control Council would be set up in Berlin. All war criminals would be punished, and Germany would be forced to pay reparations for war damages.

The conference recognized Soviet territorial claims in moving the Polish-Soviet boundary to the west. In all countries liberated from German rule, free elections were to be held. (This provision was violated by the Soviet Union, which at war's end occupied the Eastern European nations on its border and made certain that Communist regimes came to power in these countries.)

The Big Three also expressed support for a conference to be held in San Francisco, in April, 1945, to create an international organization (the United Nations [UN]) to maintain peace and security. To gain Soviet cooperation in setting up the UN, Roosevelt and Churchill gave the Soviets three seats in the organization—one for the Soviet Union as a whole, one for Byelorussia, and one for the Ukraine.

In a secret protocol, Stalin agreed to the Western leaders' request to enter the war against Japan. In return, the Soviets would be given the Japanese-held Kuril Islands, the southern half of Sakhalin, rights to lease Port Arthur and use Darien in China, and joint control with China of the railroads in Manchuria. The quick surrender of Japan after the United States dropped atomic bombs on Japan, August 7 and 9, 1945, made a previously planned invasion of Japan, and thus Soviet aid, unnecessary. The Soviet Union, however, declared war on Japan, August 8, and received the agreed-upon cessions.

The Yalta agreements were intially greeted with enthusiasm. Later, however, they were denounced by many in the West as a betrayal of Eastern Europe and China. Defenders of the accords held that Roosevelt and Churchill had no reason to believe that Stalin would not honor all the provisions and that they gave away nothing that the Soviet Union did not already control or would soon be ready to take.