Which John Ford film starred John Wayne as a PT boat commander?

They Were Expendable is the John Ford film that starred John Wayne as a PT-boat officer.

Released in 1945, the film dramatizes the experiences of Motor Torpedo Boat Squadron Three during the defense of the Philippines in 1941–42. Wayne plays Lieutenant Junior Grade Rusty Ryan, the squadron’s executive officer. Robert Montgomery plays Lieutenant John Brickley, the senior officer who commands the squadron.

The story was adapted from William Lindsay White’s 1942 best-selling book. Although fictionalized, the book and film draw on real people and events, particularly Commander John D. Bulkeley and his PT-boat unit. The boats were small, fast, wooden craft used for reconnaissance, patrols, and attacks.

The title refers to the crews’ grim wartime situation as their boats and personnel are steadily lost. A frequent mix-up is Operation Pacific, another John Wayne naval film, but it was directed by George Waggner, not John Ford.