In the spring of 1940, as World War II was intensifying, Joseph Stalin and five other prominent members of the Soviet Politburo signed a chilling directive that enabled the execution of thousands of Polish leaders and intelligentsia. This authorization specifically targeted 25,700 individuals, including 14,700 Polish prisoners of war who had been captured during the joint invasion of Poland by Nazi Germany and the Soviet Union in 1939. Within this group were educators, military officers, political leaders, and other potential sources of resistance to Soviet rule.

The decision was motivated by the Soviet leadership's desire to eliminate any intellectual, cultural, or military opposition. The Politburo viewed the Polish intelligentsia as a significant threat to their plans of establishing a communist regime in Poland, and thereby aimed to crush Polish national identity. The executions were carried out in several locations, with the most infamous site being the Katyn Forest in Russia, where mass graves would later be discovered, revealing the full scale of the atrocities committed under this order.

The aftermath of the executions had profound implications for Polish-Soviet relations and significantly shaped the historical narrative surrounding the conflict between these nations. Initially, the Soviet Union blamed the Nazis for the massacre to cover their involvement, and it wasn't until decades later, following the dissolution of the Soviet Union, that the full truth was revealed.