Although a Leninist, Castro remained critical of Marxist–Leninist Joseph Stalin, who was the Premier of the Soviet Union from 1941 to 1953. In Castro's opinion, Stalin "committed serious errors – everyone knows about his abuse of power, the repression, and his personal characteristics, the cult of personality", and also held him accountable for the invasion of the Soviet Union by Nazi Germany in 1941. At the same time, Castro also felt that Stalin "showed tremendous merit in industrializing the country" and "in moving the military industry to Siberia", things which he felt were "decisive factors" in the defeat of Nazism.