During the Second World War, John Ford served in the navy, attaining the rank of rear admiral, and made several documentaries, including the classic The Battle of Midway. When the war looked like being won, he enlisted with MGM to make They Were Expendable, a drama about buying time for the navy after the disaster of Pearl Harbor. It's an epic that follows the struggle of two officers (Robert Montgomery and John Wayne) to persuade the navy top brass that motor torpedo boats could play a useful role in the battle against the Japanese. Long, reflective and bursting with incident as the action crosses the Pacific, it contains fine performances from Montgomery, Wayne, Donna Reed and members of Ford's stock company.

After a demonstration of new PT boats, Navy brass are still unconvinced of their viability in combat, leaving Lt. "Rusty" Ryan frustrated. After the attack on Pearl Harbor, however, Ryan and his buddy Lt. Brickley are told they can finally take their squadron into battle. The PT boats quickly prove their worth, successfully shooting down Japanese planes, relaying messages between islands, and picking off a multitude of enemy ships.