This is not true. Stalin was responsible for the deaths of 3 million children in the famine of 1934 alone. There were around 6-7 million deaths in the famines of the early 30s. Then there were the purges of the late 30s. Stalin was about to start a pogrom when he died. It was his policies of destroying the Kulaks (an elastically defined scapegoat) that resulted in most of the deaths. It was Stalin's extension of Lenin's murderous tendencies that caused this. Because the system ate itself (guards became prisoners after around 18 months, and prisoners tended to die), and because the Soviet Union was never overrun like Germany some people seem to be able to ignore that the USSR was the most murderous regime in history.