Katyn Massacre (1940): The NKVD (Soviet secret police) executed thousands of Polish officers and intellectuals in the Katyn Forest. Ethnic Deportations (1940s): Entire ethnic groups (e.g., Chechens, Crimean Tatars, Volga Germans) were forcibly removed from their homelands and relocated to Siberia and Central Asia under brutal conditions. Gulag Expansion: The vast forced labor camp system continued to operate and expand, holding millions of prisoners, including political dissidents and captured soldiers. Political Purges: Even during the war, Stalin purged military commanders and political figures he deemed disloyal or a threat to his power. Post-War Expansion: Stalin established brutal Soviet-controlled regimes across Eastern Europe, including installing the North Korean government, after the war concluded.