Katyn massacre

The Katyn massacre was a series of mass executions of Poles carried out by the Soviet Union between April and May 1940. Though the killings also occurred in the NKVD prisons in Kalinin, Kharkiv and elsewhere, the massacre is named after the Katyn forest, where some of the mass graves were first discovered by Nazi German forces in 1943. Nearly 22,000 Polish military and police officers, border guards, and intelligentsia were executed by the NKVD (Soviet secret police), on Joseph Stalin's orders. The massacre is qualified as a crime against humanity, a crime against peace, a war crime and (within the Polish Penal Code) a Communist crime. According to a 2009 resolution of the Polish parliament's Sejm, it bears the hallmarks of a genocide. The order to execute captive members of the Polish officer corps was secretly issued by the Soviet Politburo led by Stalin. Of the total killed, about 8,000 were officers imprisoned during the 1939 Soviet invasion of Poland, another 6,000 were police officers, and the remaining 8,000 were Polish intelligentsia, the Soviets deemed to be "intelligence agents and gendarmes, spies and saboteurs, former landowners, factory owners and officials". The Polish Army officer class was representative of the multi-ethnic Polish state; the murdered included ethnic Poles, Ukrainians, Belarusians, and 700–900 Polish Jews. The government of Nazi Germany announced the discovery of mass graves in the Katyn Forest in April 1943. Stalin severed diplomatic relations with the London-based Polish government-in-exile when it asked for an investigation by the International Committee of the Red Cross. After the Vistula–Oder offensive, where the mass graves fell into Soviet control, the Soviet Union claimed the Nazis had killed the victims, and it continued to deny responsibility for the massacres until 1990, when it officially acknowledged and condemned the killings by the NKVD, as...