They Were Expendable is a 1945 American war film directed by John Ford and starring Robert Montgomery and John Wayne and featuring Donna Reed. The film is based on the book by William L. White, relating the story of the exploits of Motor Torpedo Boat Squadron Three, a PT boat unit defending the Philippines against Japanese invasion during the Battle of the Philippines (1941–42) in World War II. While a work of fiction, the book was based on actual events and people.