Stanley Kubrick started with nothing but a vague idea to make a thriller about a nuclear accident, building on the widespread Cold War fear for survival.[23] While doing research, Kubrick gradually became aware of the subtle and unstable "balance of terror" between nuclear powers. At Kubrick's request, Alastair Buchan (the head of the Institute for Strategic Studies), recommended the thriller novel Red Alert by Peter George.[24] Kubrick was impressed with the book, which had also been praised by game theorist and future Nobel Prize in Economics winner Thomas Schelling in an article written for the Bulletin of the Atomic Scientists and reprinted in The Observer,[25] and immediately bought the film rights.[26] In 2006, Schelling wrote that conversations between Kubrick, Schelling, and George in late 1960 about a treatment of Red Alert updated with intercontinental missiles eventually led to the making of the film.[27]
In collaboration with George, Kubrick started writing a screenplay based on the book. While writing the screenplay, they benefited from some brief consultations with Schelling and, later, Herman Kahn.[28] In following the tone of the book, Kubrick originally intended to film the story as a serious drama. But, as he later explained during interviews, he began to see comedy inherent in the idea of mutual assured destruction as he wrote the first draft. Kubrick said:
My idea of doing it as a nightmare comedy came in the early weeks of working on the screenplay. I found that in trying to put meat on the bones and to imagine the scenes fully, one had to keep leaving out of it things which were either absurd or paradoxical, in order to keep it from being funny; and these things seemed to be close to the heart of the scenes in question.[29]
Among the titles Kubrick considered for the film were Dr. Doomsday or: How to Start World War III Without Even Trying, Dr. Strangelove's Secret Uses of Uranus, and Wonderful Bomb.[30] After deciding to make the film a black comedy, Kubrick brought in Terry Southern as a co-writer. The choice was influenced by reading Southern's comic novel The Magic Christian, which Kubrick had received as a gift from Peter Sellers,[4] and which itself became a Sellers film in 1969