Off Limits (1988)
Off Limits is a 1988 action-thriller film set during the Vietnam War starring Willem Dafoe and Gregory Hines and directed by Christopher Crowe. The term "off limits" referred to the area where the original crime took place, an area of Saigon off limits to military personnel. The name of the film was changed to Saigon or Saigon: Off Limits when it was released throughout the rest of the world.
More at Wikipedia.