Peter Tarnoff, a seasoned diplomat whose work behind the scenes for presidents Jimmy Carter and Bill Clinton included establishing a secret channel to Fidel Castro and helping arrange the escape of six U.S. Embassy officials from Iran, an escapade later depicted in the 2012 movie “Argo,” died on Nov. 1 at his home in San Francisco. He was 86.

While other outsized personalities like Richard Holbrooke and Anthony Lake became famous, Mr. Tarnoff preferred to wield his influence out of the public eye. “Peter was really the quintessential diplomat in the sense that he never asked for the spotlight,” said Wendy Sherman, who served alongside him in the Clinton administration. “He never needed to be the named person. He just got the job done.”