The film is set in 1943, in a POW camp in Burma, along the route of a rail line the Japanese were building between Malaysia and Rangoon. Seen through the eyes of Colonel Nicholson (Alec Guinness), commanding officer of a battalion of British war prisoners, the war narrows to a single task, building a bridge across the Kwai. The film then focuses on exactly what the viewer considers to be mad. For Shears, an American sailor, (William Holden), madness would be returning to the jungle. For Col. Saito (Sessue Hayakawa), the Japanese commandant of the camp, madness and suicide are never far away as the British build a better bridge than his own men could. Finally for Clipton (James Donald), the army doctor who says the final words, they could simply mean that the final violent confusion led to unnecessary death.
Nicholson and Saito, the commandant, are quickly involved in a faceoff. Saito wants all of the British to work on the bridge. Nicholson says the Geneva Convention states officers may not be forced to perform manual labor. He even produces a copy of the document, which Saito uses to whip him across the face, drawing blood. Nicholson is prepared to die rather than bend on principle, and eventually, in one of the film's best-known sequences, he's locked inside ‘the Oven’, a corrugated iron hut that stands in the sun.
The story in the jungle moves ahead neatly, economically and powerfully. There is a parallel story involving Shears, following his escape, is taken to a hospital in British occupied Ceylon, drinks martinis and frolics with a nurse, and then is asked by Major Warden (Jack Hawkins) to return as part of a commando team to blow up the bridge. Holden is extremely good as the malingerer and unlikely hero – you see his character come full circle as the film ends. Note should be made of Hawkins brilliant, perhaps his finest role, as the focused British commando. With all Hawkins military characters you really have faith that he is who he plays. The long match where he refuses to be carried is a good example of the stiff upper lipism that he carries so well. He and Holden handle the British humour well with Hawkins providing foil lines such as ‘Jolly good show’ to which Holden replies ‘yes jolly good show, jolly jolly good…good hunting’ in perhaps the most humorous moment of the film.
The film's central relationship is between Saito and Nicholson, a professional soldier approaching his 28th anniversary of army service ‘I don't suppose I've been at home more than 10 months in all that time’. The Japanese colonel is not a military pro; he learned English while studying in London. But he is a rigidly dutiful officer, and we see him weeping privately with humiliation because Nicholson is a stronger willed man – a great insult to a Japanese officer.
Most war movies are either for or against their wars. This film is one of the few that focuses not on rights and wrongs but on individuals. Like Robert Graves' World War I memoir, Goodbye to All That, it shows men grimly hanging onto military discipline and pride in their units as a way of clinging to sanity. By the end of the film we are less interested in who wins than in how individual characters will behave.
The scenes in the jungle are crisply told. We see the bridge being built, and we watch the standoff between the two colonels. Hayakawa and Guinness make a good match as they create two disciplined officers who never bend, but nevertheless quietly share the vision of completing the bridge.