On August 8, 1945, a Soviet army of 1.5 million troops invaded Northern China, an area the size of western europe. They engaged and encircled the Japanese Kwantung Army, and obliterated 1 million fighting men of the Japanese. Japan heavily depended on the resources they had in Northern China to continue the war against the United States and China.

So was dropping the atomic bombs more influential to Japanese surrender, or the Soviets invading Northern China (which, incidentally, set up the Chinese Communist victory over the Nationalists in 1949 and also the Korean War in 1950).

Saw this in the news, thought I might bring it up here.