 Strickler had continued his military service as a member of the Organized Reserve after the first World War, receiving promotion to captain in 1918, major in 1922, lieutenant colonel in 1928, and colonel in 1935.He graduated from the United States Army Command and General Staff College, and from 1935 to 1938 he commanded the 313th Infantry Regiment, a unit of the 79th Infantry Division.From 1938 to 1942 he commanded the division's 158th Infantry Brigade.