Lieutenant General Trainor commanded in combat in Korea and on two tours in Vietnam. His final Marine Corps position was Chief of Staff for Plans, Policies and Operations and Marine Corps Deputy to the Joint Chiefs of Staff. Retiring in 1985, he joined The New York Times as its military correspondent. Among his publications is Cobra II: The Inside Story of the Invasion and Occupation of Iraq (2006), coauthored with Michael Gordon. They are working on another book about the Iraq wars.