United States Army General. He graduated from the United States Military Academy at West Point, New York in 1943, and was assigned as a 2nd Lieutenant and company commander in the European Theatre during World War II. After the war he served in a number of various posts in Europe and the Pacific, rising in the ranks until he was promoted to Lieutenant General. From 1967 to 1969 he served as commander of United States Special Forces in the Pacific, from 1973 to 1977 as Assistant Chief of Intelligence for the Department of the Army, and from 1977 to 1979 as deputy director of the Defense Intelligence Agency. He was decorated with the Distinguished Service Medal and the Legion of Merit with 2 Oak Leaf Clusters during his service.

As a colonel, Aaron served as Commander, 5th Special Forces Group (Airborne) in Vietnam from June 4, 1968 to May 8, 1969. From November 5, 1973 to August 28, 1977, he served as the Assistant Chief of Staff for Intelligence, Headquarters, Department of the Army as a Major General. He later was promoted to Lieutenant General.