From July 17 to August 2, 1945, President Harry S. Truman (1884-1972; see entry in volume 4), British prime minister Winston Churchill (1874-1965; see box in Harry S. Truman entry in volume 4), his successor, Clement Attlee (1863- 1967), and Soviet premier Joseph Stalin (1879-1953) met in Potsdam, Germany, to discuss the future of Germany and to plan strategies against Japan. It was more than two months after Germany had surrendered; World War II (1939-45) in the European Theater was over. Truman received a promise from Stalin that the Soviet Union (USSR) would enter the war against Japan.

Meanwhile, the first atomic bomb was tested on July 16, 1945, at Alamogordo, New Mexico. Truman informed Churchill that the United States had successfully detonated the weapon and had built several more.

On July 26, the Allied Powers meeting at Potsdam...