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
Polish Operation of the NKVD of the Polish diversionist and espionage groups and POW units"," was approved on August 9, 1937 by the Party's Central Committee Politburo, and was signed by Nikolai Yezhov on August 11, 1937. It was distributed to the local subdivisions of the NKVD simultaneously with Yezhov's thirty-page "secret letter," explaining what the "Polish operation" was all about. The letter from Yezhov was titled, ""On fascist-resurrectionist, spying, diversional, defeationist, and terrorist activity of Polish intelligence in the USSR"". Stalin demanded the NKVD to "keep on digging out and cleaning out this Polish filth." The "Order" adopted the simplified so-called "album procedure" (as