The Katyn massacre cover-up

For decades, the Soviet Union maintained that the Nazis were responsible for the killings at Katyn, but the story eventually changed. In 1940, around 22,000 Polish military personnel and civilians were executed in what became known as the Katyn massacre, with responsibility later attributed to Stalin's secret police, the NKVD.

The Soviet explanation remained in place for roughly half a century, despite growing evidence challenging it. Then in 1990, Mikhail Gorbachev acknowledged that the NKVD was responsible for the massacre, marking a dramatic reversal of the official Soviet position.

The admission was followed by a declaration from Russia's parliament that Stalin had ordered the executions. What makes Katyn particularly significant is not only the scale of the killings, but the decades long effort to attribute them to someone else. A massacre involving thousands of Polish victims had been accompanied by an official version of events that was eventually abandoned by the same state that had promoted it.