At the U.S. naval base at Guantanamo Bay, Cuba, two Marines, Dawson and Donnie, were accused of killing another soldier, Santiago. Navy lawyer Daniel Caffey (Tom Cruise) and his assistant Sam were assigned to take over the case. They found out that Santiago had hoped to be transferred from the base and had reported Dawson. Caffey wanted to negotiate out of court for a two-year sentence. However, the two soldiers insisted that they were innocent. Their actions against Santiago were the "red regulations" issued to them by their superiors. The so-called red regulations are a kind of admonition regulations that are tacitly approved by officers and carried out privately by soldiers. Caffey, Sam and another female lawyer, Galloway (Demi Moore), formed the defense lawyers to investigate, while the base commander Colonel Jessup (Jack Nicholson) was the key figure in the case. He rejected Santiago's application for transfer, issued him a "red regulation", and privately tampered with the flight records afterwards. Although Caffey knows the truth, he is troubled by insufficient evidence. In this case, if he testifies against Colonel Jessup, it will bring trouble to himself. What will be the outcome of this lawsuit about justice?