 He was promoted to major in January 1951, and was transferred to Headquarters Marine Corps in June of that year, where he served as head, Enlisted Promotion Section, Personnel Department.In September 1952, Dwyer was ordered to Korea.During the Korean War, he served as executive officer (XO) of the USMC Advisory Groupto the 1st Korean Marine Corps Regiment; As S-3, 5th Marines; Assistant G-3 (Ops) and Assistant G-3 (Plans) for the 1st Marine Division.