In Saigon in 1952, as Vietnamese insurgents are delivering major strikes against the French colonial rulers, an innocent and enigmatic young American economist (Audie Murphy), who is working for an international aid organization, gets caught between the Communists and the colonialists as he tries to win the "Hearts and Minds (Vietnam)" of the Vietnamese people. By promising marriage, he steals away a young Vietnamese woman (Giorgia Moll) from an embittered and cynical English newspaperman (Michael Redgrave), who retaliates by spreading the word that the American is actually covertly selling arms to the anti-Communists.