The Soviet Union was responsible for the Katyn massacre of 22,000 Polish officers, and the imprisonment or execution of thousands of political prisoners by the NKVD, along with mass civilian deportations to Siberia, in the Baltic states and eastern Poland annexed by the Red Army.
A Unión Soviética foi responsable do masacre de Katyń, na que faleceron uns 22 000 polacos, e do apresamento e execución de miles de prisioneiros políticos por parte da NKVD nos estados Bálticos e Polonia oriental anexionados polo Exército Vermello.