The film, set in 1972, was inspired by an actual incident which occurred on 17 January 1966: a B-52G Stratofortress collided with a KC-135 Stratotanker over Palomares, Spain, and four B-28 FI 1.45-megaton-range hydrogen bombs aboard the B-52 were briefly lost. In a title sequence shot by Maurice Binder, a chorus of Spanish Flamenco dancers explains why the film's location is Greece rather than Spain.