The Americans desperately did not want Stalin to get his hands on Japan’s amazing and efficient military and industrial factories or scientists. History show how the Americans and Russians made use of Nazi scientist but post war Japan was America’s possession exclusively.Did the atomic bombs actually forced the insane military dictatorship to surrender or was something else at play.
The Red Army had conquered the Japanese south of Sakhalin Island which was given to Japan as compromise after the Russo-Japanese War in 1906. The Russians had built up a massive flotilla to invade Hokkaido which they went ahead with. The Russians were in the process of taking Hokkaido when Japan surrendered. Becoming Viceroy of Japan, General McArthur ordered the Russians out of Japan. Stalin blinked, it was the first time. He would blink again in Korea and Mao had to clean up his mess.