He joined the Russian Social Democratic Labour Party (b) in 1917 and, after the October Revolution, began recruiting Red Guards in Bessarabia. During Operation Faustschlag in March 1918 he was injured and taken captive by the Central Powers. He escaped in August, joined the Red Army, and served as an artillery instructor and commander of the Dvinsk Brigade on the Northern Front. In December 1918 he received command of the 18th Rifle Division of the 6th Army.