During the
Russian Civil War, he joined the
Mtsensk Red Guard detachment in October 1917 and was appointed a platoon commander in it. With the detachment, he took part in the disarmament of the
junkers and cadets in Oryol. In February 1918 the detachment was reorganized into the 1st Red Guard Soviet Regiment of the
Red Army. That month he was sent to instructor courses in Yaroslavl, and after graduation remained at the courses to retrain officers of the imperial army. With the courses, he took part in the suppression of the
Yaroslavl rebellion from 6 to 21 July 1918, and in the fighting with the armed bands led by Sotnikov. After the disbandment of the courses in August 1918 he was sent to the 7th Yaroslavl Regiment. In December, he went to the
Northwestern Front with the regiment, where he fought as a platoon and company commander. In April 1919 he was dispatched to the
Novgorod Infantry Courses for Red Commanders. During training he twice left with the courses to the Petrograd front, where he took part in the battles with the
Northwestern Army in the areas of
Strelna,
Ligovo,
Gatchina,
Pulkovo, and
Yamburg. After graduating from the courses in October 1919 he went to the
Southern Front with the 7th Yaroslavl Regiment, where he fought against the
Army of Wrangel as commander of a platoon and company of cadets. In battle near
Tokmak he was captured by the Whites. He spent 23 days in captivity before escaping. From July 1920 he fought as a company and battalion commander with the 337th Rifle Regiment of the 42nd Rifle Division. He took part in the battles against the
Dashnaks in the Transcaucasus between September and November 1920, and against the
Makhnovites in Ukraine. That year in battle near Andreyevka he was captured by the Makhnovites, escaping two days later. From March 1921, Korotkov commanded a company of the 126th Regiment of the Reserve of Command Personnel in Mozdok. After the disbandment of the regiment he was sent to serve in the same position in the 21st Rifle Regiment of the
20th Rifle Division at
Prokhladnaya. ==Interwar period==