After basic training, he served as a platoon leader at San Diego Marine Corps Base, then served in the South Pacific with the 2nd Marine Brigade during World War II, seeing action in Guadalcanal, Vella Lavella, and Bougainville as a rifle company commander. He was hospitalized briefly from injuries sustained in Bougainville and then joined the 1st Marine Division in time for landings on Peleliu and, later, Okinawa, where he was again wounded in action. He was a lieutenant colonel commanding an infantry battalion training for the invasion of Japan when the war ended.