The movie wasn’t made, but Fleming, who had actually been the one to come up with the title, ended up using elements of Thunderball for his own James Bond novel.
The story of Warhead is actually the story of a much better known James Bond story, Thunderball.
McClory sued Fleming and won, which resulted in McClory owning the film rights to the story.
Back in 1958, before any James Bond novels had been turned into films, a man named Kevin McClory and another screenwriter wrote, with Ian Fleming’s blessing, an original Bond story that was going to be the first Bond movie.