Allied intervention in the Russian Civil War Powers to withdraw from North Russia and Siberia in 1920, though Japanese forces occupied parts of Siberia until 1922 and the northern half of Sakhalin until 1925. In 1917, Russia was in a state of political strife, and public support for World War I and the Tsar was dwindling. The country was on the brink of revolution. The February Revolution changed the course of the war; under intense political pressure, the Tsar abdicated and the Russian Provisional Government was formed, led initially by Georgy Lvov and later by Alexander Kerensky. The Provisional Government pledged to continue fighting the Germans on
NKVD political prisoners in 1939–1941, including the Katyń massacre. NKVD units were also used to repress the prolonged partisan war in Ukraine and the Baltics, which lasted until the early 1950s. After the death of Stalin in 1953, the new Soviet leader Nikita Khrushchev halted the NKVD purges. From the 1950s to the 1980s, thousands of victims were legally "rehabilitated" (i.e., acquitted and had their rights restored). Many of the victims and their relatives refused to apply for rehabilitation out of fear or lack of documents. The rehabilitation was not complete: in most cases the formulation was "due to lack of