Men Must Fight is a 1933 American Pre-Code drama film starring Diana Wynyard, Lewis Stone and Phillips Holmes. It is based on the 1932 Broadway play of the same name by Reginald Lawrence and S. K. Lauren. When her lover is killed in World War I, a woman raises their son as a pacifist. However, when a second world war looms "between the United States and a country referred to as the Eurasian States in 1940", that belief is put to the test.