The Soviet government officially accepts blame for the Katyn Massacre of World War II, when nearly 5,000 Polish military officers were murdered and buried in mass graves in the Katyn Forest. The admission was part of Soviet leader Mikhail Gorbachev's promise to be more forthcoming and candid concerning Soviet history.
In 1939, Poland had been invaded from the west by Nazi forces and from the east by Soviet troops. Sometime in the spring of 1940, thousands of Polish military officers were rounded up by Soviet secret police forces, taken to the Katyn Forest outside of Smolensk, massacred, and buried in a mass grave. In 1941, Germany attacked the Soviet Union and pushed into the Polish territory once held by the Russians. In 1943, with the war against Russia going badly, the Germans announced that they had unearthed thousands of corpses in the Katyn Forest. Representatives from the Polish government-in-exile (situated in London) visited the site and decided that the Soviets, not the Nazis, were responsible for the killings. These representatives, however, were pressured by U.S. and British officials to keep their report secret for the time being, since they did not want to risk a diplomatic rupture with the Soviets. As World War II came to an end, German propaganda lashed out at the Soviets, using the Katyn Massacre as an example of Russian atrocities. Soviet leader Joseph Stalin flatly denied the charges and claimed that the Nazis were responsible for the slaughter. The matter was not revisited for 40 years.
By 1990, however, two factors pushed the Soviets to admit their culpability. First was Gorbachev's much publicized policy of "openness" in Soviet politics. This included a more candid appraisal of Soviet history, particularly concerning the Stalin period. Second was the state of Polish-Soviet relations in 1990. The Soviet Union was losing much of its power to hold onto its satellites in Eastern Europe, but the Russians hoped to retain as much influence as possible. In Poland, Lech Walesa's Solidarity movement was steadily eroding the power of the communist regime. The Katyn Massacre issue had been a sore spot in relations with Poland for over four decades, and it is possible that Soviet officials believed that a frank admission and apology would help ease the increasing diplomatic tensions. The Soviet government issued the following statement: "The Soviet side expresses deep regret over the tragedy, and assesses it as one of the worst Stalinist outrages."
Whether the Soviet admission had any impact is difficult to ascertain. The communist regime in Poland crumbled by the end of 1990, and Lech Walesa was elected president of Poland in December of that year. Gorbachev resigned in December 1991, which brought an effective end to the Soviet Union.