How did the soviet invaion of manchuria influence japan decision to surrender?

Answer 1

The Japanese government had been talking to the Soviet government in an attempt to broker a negotiated peace with the Allied nations. The Soviets were not at war with Japan in the spring of 1945, since they had their hands full with Germany. After the German surrender in May 1945, the Soviet Union had promised the West they would declare War on Japan at the beginning of August 1945.

The US Secretary of War Stimson and the atom bomb builder General Groves felt three great shocks would bring the Japanese to the surrender table. One shock was the declaration of war by the Soviets and the plunge into Manchuria, while the second and third shocks were the two atom bomb strikes. This left the Japanese Government at a tie vote in the Cabinet. At this point the peace faction asked the Japanese Emperor for his opinion. He said Japan must surrender.