While Coppola did portray insanity and madness, these qualities sprang from the nature of the characters he chose to create, and were not strongly linked to the purpose or nature of U.S. involvement in Vietnam -- which was not even touched upon in the film.
The theme was developed largely around two characters: Captain Willard (Martin Sheen) and Colonel Kurtz (Marlon Brando). Kurtz, once a Green Beret with a top service record, had apparently gone stark raving mad. He had set himself up as an exalted leader of a primitive band of Cambodian tribesmen, and began following an independent path of murder, for reasons known only to himself. Willard was ordered to venture upriver into Cambodia, track down Kurtz, and assassinate him.
Coppola added thoughts, in Sheen's voice, to the sound track in order to develop Willard's character. But Willard never really becomes more than a man with a mission, as the film proceeds through a series of scene changes which convey the violence and contrasts. His character develops in the following scenes: from a room in Siagon, to a helicopter a helicopter assault on a Vietnamese village, to a USO show featuring Playboy Bunnies, to aimless drugged-up soldiers lacking command, and finally to kurtz's kingdom in the jungle.
The structure of the film was based on these contrasts. Neither Willard nor Kurtz had any relevance to the scenes, except