He graduated from Colgate in 1958 with a degree in philosophy, a subject he continued to pursue at the Committee on Social Thought, a doctoral program at the University of Chicago. But his interest in global affairs pulled him away from academia, and he joined the Foreign Service in 1962.
Mr. Tarnoff’s first marriage, to Danielle Oudinot, ended in divorce. He married Ms. Falco in 1982. Along with her, he is survived by a son from his first marriage, Alexander; a son from his second, Benjamin; his half brother, John Tarnoff; and three grandchildren. Another son with Ms. Oudinot, Nicholas, died in 1991.
After an initial posting to Lagos, Nigeria, Mr. Tarnoff moved to Saigon (now Ho Chi Minh City), the capital of South Vietnam. In 1965 he was seriously wounded by flying glass when a car bomb detonated beside the U.S. Embassy, killing two inside and 20 on the street.
During the 1970s he held a variety of posts around Europe before moving to Washington in 1975.
After Ronald Reagan defeated Mr. Carter in the 1980 presidential election, tradition dictated that the incoming administration would take care of Mr. Tarnoff, who was both a nonpolitical Foreign Service officer and a confidante of one of the previous administration’s leading Cabinet members.