Taken as a whole, the Soviet Union in the 1930s and 1940s was certainly not in Nazi Germany's league as a threat to humans.
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In the 1930s, up until September 1939, and maybe even afterwards, through the "phony war," there is no question that Stalinist Russia was a more serious threat to human life and limb. The Hitler regime was repressive but not murderous on a mass scale up through the start of the war, and indeed, really the mass killing did not start till the invasion of Russia in 1941. --jks