From 1985, he served in the 44th Training Airborne Division in Jonava, Lithuanian SSR. He graduated from the Sverdlovsk Higher Military-Political Tank-Artillery School in 1986, and entered service in the airborne, tank and motorized rifle units of various military districts, including the Turkestan Military District. From 1987 to 1989, he fought in the Soviet–Afghan War as part of the 103rd Guards Airborne Division. Stvolov then participated in the localization of interethnic armed conflicts of the First Nagorno-Karabakh War, Transnistria War, and the Tajikistani Civil War. As a battalion commander, he fought in the First Chechen War, and was awarded the Order of Courage three times. Stvolov was seriously wounded during the Battle of Grozny in January 1995. He was hospitalized, but then escaped from the hospital to return to the battle.