Colin Clarke served in the U.S. Naval Reserved while completing his bachelor’s degree at the University of Washington. After graduation he was discharged in order to attend the Air Force OTS program, earning his commission and subsequently earning his wings. He served his first tour of duty in Vietnam in 1962-63, and a second tour in 1964-65. He earned the Silver Star on his third Vietnam tour in 1968-69, and the Air Force Cross during his fourth tour in Vietnam in 1972-73. In all he completed 385 combat missions in Southeast Asia, and was shot down and rescued twice. He later served with the Military Assistance Advisory Group in Tehran, Iran, until he was evacuated due to the revolution that led to the Iranian hostage crisis. He retired from the Air Force on August 1, 1981.