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 known as the GULag) as well as the regular police. At various times, the NKVD had the following Chief Directorates, abbreviated as "ГУ"– , . Until the reorganization begun by Nikolai Yezhov with a purge of the regional political police in the autumn of 1936 and formalized by a May 1939 directive of the All-Union NKVD by which all appointments to the local political police were controlled from the center, there was frequent tension between centralized control of local units and the collusion of those units with local and regional party elements, frequently resulting in the thwarting of Moscow's plans.