 During the World War II period, the two countries suffered more losses than any other country, with China (in the Second Sino-Japanese war) losing about 30 million people and the Soviet Union 26 million.On August 8, 1945, three months after Nazi Germany surrendered, and on the week of the American Atomic bombings of Hiroshima and Nagasaki, the Soviet Union launched the invasion of Manchuria, a massive military operation mobilizing 1.5 million soldiers against one million Kwantung Army troops, the last remaining Japanese military presence.Soviet forces won a decisive victory while the Kwantung suffered massive casualties, with 700,000 having surrendered.