Show Trials and the Great Purges
Stalin began to become paranoid. He feared being overthrown or the threat of a counter revolution. He formed a secret police called the NKVD to remove any and all possible threats. The secret police later became known as the KGB. All of the Old Heroes of the revolution or basically anybody with popular support was charged with treason. They were either killed or sent to Gulags in Siberia. They would die either way. 1 in 5 officers of the army ended up being executed. This caused many, many problems when world war II came around. They were also often put on trial called "Show Trials." Here the people were forced to admit that they had done what they were charged with, even if they were innocent. If somebody did not plead guilty, they would bring in family member's and close friends, and threaten to kill them on the spot if they did not plea guilty.