On returning to the United States after his first tour at the University of Oxford, he joined the
82nd Airborne Division, where in 1965 he commanded an engineer company in the
Dominican Republic. He saw combat in
Vietnam from 1968 to 1969, where he was an Engineer Battalion S-3 and assistant division engineer for the
First Cavalry Division. After his second tour at the University of Oxford, Graves returned to West Point in 1970. He was assigned to the Department of Social Sciences, where he taught international relations and comparative foreign governments. In 1974, Graves was appointed
military assistant to the Secretary of Defense,
James Schlesinger. His duties included coordinating Schlesinger's travel and public appearances, preparing briefings and speeches for Congressional hearings, and providing counsel on matters affecting the U.S. Army. In 1976, Graves took command of the 54th Engineer Battalion in
West Germany, returning to the United States in 1978 to attend the
Army War College at
Carlisle Barracks,
Pennsylvania. In 1980, Graves took command of the 20th Engineer Brigade. He then joined the
First Infantry Division in 1982 as the assistant division commander. The next year, Graves was appointed deputy chief of staff, engineer, U.S. Army Forces Command. In 1984, Graves was promoted to
brigadier general and became deputy director for strategy, plans, and policy, of the Army Staff. The next year he was promoted to vice director of the Joint Staff. In 1987, Graves succeeded
James E. Thompson Jr. as commandant of the Army War College.
Lieutenant General Graves then returned to
Washington, D.C., to become assistant to the chairman,
Joint Chiefs of Staff. In 1991, Graves was appointed the 54th superintendent of the United States Military Academy, a position he held until his retirement in 1996. ==Later life and death==