Soviet attack on Japan

On the night of 8-9 August 1945, in conformance with agreements made at the Yalta Conference, the Soviet Union attacked the Empire of Japan, using 1.5 million troops on a 2730 mile front. Earlier in the day, the first of the nuclear attacks on Japan had taken place, and the United States would have preferred the Soviets to stay out. A number of analysts, however, believe the Soviet attack, either in combination with the nuclear attacks or on its own, may have been a major factor in the decision for the surrender of Japan.

Soviet Foreign Minister Molotov received Ambassador Sato on 29 May, and told him that nothing had happened at Yalta that should alarm Japan, and said that the Soviet abrogation of the 1941 Soviet-Japanese Neutrality Pact was a formality. Sato appeared to believe him, although the U.S. MAGIC commentary on Sato's report to Tokyo was "[T]he meeting leaves a mental picture of a mastiff who also knows where the bone is buried."