A cold war film about an error in the entrenched missile systems of USA and the Soviet Union which triggers a nuclear exchange. A computer malfunction fails to step down a resolved warning on America's satellite surveillance, releasing warheads which no human is able to recall.
Critics feel that this bombed at the box office because Dr. Strangelove was released earlier the same year and satirised a plot that Fail-Safe played for real. But it may also be because Sidney Lumet's film is quite cerebral and loaded with theory. Every aspect of the ethics and efficiency of the nuclear stand-off is discussed. Walter Matthau's character even delivers a lecture!
Though the themes are complex, they are interesting and accessible. And once the missiles are in transit to Moscow the film becomes incredibly tense as the President (Henry Fonda) ironically tries to help the Soviets shoot down American bombers. And then tragic as he negotiates a horrifying recompense for American bombs and the loss of five million lives.
There is no action in Fail-Safe, but it is one of the greatest war films ever made. It is always relevant. Fonda was born to play the US President, and pre-stardom Matthau is convincingly malevolent as a war games consultant who recommends exploiting the accident to start a conflict which will end Soviet communism. It's a story that seeks to educate, but it is also a phenomenally suspenseful encounter with the ultimate catastrophe.