After World War 2, Hitler was going already and then he took over Russia. He kept some of the concentration camps and he killed over 10,000 people (not just jews). I also though he took over some countries and then they became Communist countries.
By creating what people call Stalinism. A cult of Stalin was developed which included six main objectives - command economy whereby the state controls most of soviet life -politicisation of life -social structure, so all were equal in the state -culture was controlled by propaganda Revolutionary conservatism As a result of the cult of Stalin he was able to keep in power and rule over the USSR easier