At the time of his death in a command helicopter crash near the Cambodian border, he was viewed as the dean of the Saigon press corps.

Sully was born on 27 August 1927 in France and fought against the Nazis in the French Resistance as a teenager and was wounded on his seventeenth birthday in Paris.

In March 1962, Sully was to be expelled from South Vietnam by President Ngo Dinh Diem, egged on by Madame Nhu, as his reporting was deemed "helpful to the enemy".

Unofficially, Diem intended the expulsion to serve as a warning to all journalists reporting the failings of his U.S.-assisted war against the Viet Cong.

After his expulsion Sully proceeded to Harvard where he put in a year at the Nieman Foundation and worked in bordering countries to Vietnam.

During his work as Newsweek's Saigon Bureau Chief, Sully also wrote for a number of other newsmagazines including The Nation and The New Republic.

On 23 February 1971 he was aboard the command helicopter of General Do Cao Tri (the 'Patton of the Parrots Beak') as it turned west towards Cambodia.