 It withdrew from the First World War by signing a treaty conceding territory to the Central Powers, and promoted world revolution through the Communist International.Opponents were suppressed in the Red Terror, a violent campaign administered by the state security services; tens of thousands were killed or interned in concentration camps.His administration defeated right and left-wing anti-Bolshevik armies in the Russian Civil War from 1917 to 1922 and oversaw the Polish–Soviet War of 1919–1921.