Col. Rheault was a 1946 graduate of the U.S. Military Academy at West Point. During the 1950s, he received a Bronze Star Medal in the Korean War, studied at the Sorbonne in Paris and was head of the French department at West Point. He joined the Army's Special Forces in 1960. He traveled all over the world, engaging in actions along the East German border and peering into China from high in the Himalayas. He trained military units in Jordan, Pakistan, Tunisia and Iran. During Col. Rheault's first tour in Vietnam in 1964, he was an intelligence and operations officer with the Green Berets. In the mid-1960s, when he received a master's degree in international relations from George Washington University, Col. Rheault also worked as a counterinsurgency specialist for the Joint Chiefs of Staff. He had close contact with top officials at the White House, State Department, Pentagon and CIA. He was among the few people who knew about clandestine U.S. operations in Vietnam and neighboring Cambodia and Laos. He retired from the Army on his 44th birthday, October 31, 1969.