Soviets survived the Nazis in huge part to US support, FDR's lend-lease aid program; massive amounts of tanks, planes, cars, trucks, heavy guns, diesel generators, food, medical supplies etc (in which the British broke faith, backed out and didn't help).
MacArthur wouldn't invade Japanese islands without Russia invading Manchuria first. After losing 25m to Nazi Germany the Soviets stepped up, opened a new war with Japan and saved "2m American serviceman lives"
