In 1947, he founded the literary review Caliban, adopted the pen name Jean Daniel and was the editor until 1951. In 1948, with permission, he republished essays by Sartre, Camus and other intellectuals that had first appeared in the polemical journal Esprit. Camus wrote an introduction to Mr. Daniel’s first novel, “L’Erreur” (1953).
Mr. Daniel married Michèle Bancilhon in 1966. In addition to his wife, he is survived by a daughter, Sara Daniel, a reporter at L’Obs.
In the late 1950s, Benjamin C. Bradlee, a future executive editor of The Washington Post who was then a correspondent in France for Newsweek, became acquainted with Mr. Daniel through mutual contacts in the Algerian guerrilla group FLN. It was Mr. Bradlee, a longtime friend of Kennedy’s, who suggested Mr. Daniel when the president needed a private go-between to carry his proposal to Castro in 1963.
In a meeting at the White House, Kennedy asked Mr. Daniel to convey his view that improved relations were possible, and that the president was willing to authorize exploratory talks. Mr. Daniel met Castro in Havana on Nov. 19. He said that Castro listened with “devouring and passionate interest” and expressed cautious approval of such talks.
Three days later, after learning that the president had been slain, Castro told Mr. Daniel, “They will have to find the assassin quickly, but very quickly, otherwise, you watch and see, I know them, they will try to put the blame on us for this thing.”
After the announcement of Oswald’s arrest, Mr. Daniel recalled, “The word came through, in effect, that the assassin was a young man who was a member of the Fair Play for Cuba Committee, that he was an admirer of Fidel Castro.”
The Warren Commission’s investigation of the assassination concluded in 1964 that Oswald had acted alone in killing Kennedy and that Jack Ruby had acted alone in killing Oswald two days later. Its report has been challenged and defended over the years.
The stalemate between Cuba and the United States, meanwhile, was continued by eight American presidents until Mr. Obama and President Raúl Castro, Fidel’s brother and successor, agreed on Dec. 17, 2014, to establish diplomatic relations, sweeping aside one of the last vestiges of the Cold War.
Constant Mehéut contributed reporting.