Truman, supremely confident because he had unilateral possession of the atomic bomb, tried to dictate postwar terms in Eastern Europe to the Soviet Union. A month after Hiroshima, the Soviets rejected U.S. demands backed by the bomb at the London Council of Foreign Ministers. John Foster Dulles, who attended the London meeting, regarded it as the beginning of the Cold War.[128] President Truman then announced in September 1945 that he was not interested in seeking international control over nuclear weapons.
