Bullet in the Head (1990), directed by John Woo, is a Hong Kong war drama starring Tony Leung Chiu-wai, Jacky Cheung and Waise Lee. The film follows three friends who flee to Vietnam and become entangled in the violence of the Vietnam War. Known for its intense storytelling and large-scale action sequences, the film reflects Woo’s early work before his Hollywood breakthrough.

Från IMDB:
When three close friends escape from Hong Kong to war-time Saigon to start a criminal's life, they all go through a harrowing experience which totally shatters their lives and their friendship forever.