Although it's rather long and tedious in spots, and has the strong flavor of World War II propaganda, the 1941 Gary Cooper movie, Sergeant York, has an important message for today. Based on the true story of World War I hero Sergeant Alvin York, the movie was released in July 1941, before Pearl Harbor, when the majority of Americans, including notable celebrities, felt we should mind our own business and leave Hitler alone. The movie had a worthwhile message then, and it has a worthwhile message now.
Alvin York was a pacifist who was drafted in World War I but had his conscientious objector status denied because he belonged to a small independent Christian sect that wasn't recognized as an organized religion. During one point in the movie, recognizing the Tennessee woodsman's talent as a marksman, two of his commanding officers try to persuade him to accept a promotion. He has declined it because it would force him to command others to kill. One officer attempts to argue with Scripture, and fails miserably. Finally, the other one takes down a book called the History of the United States and hands it to York, telling him:
That's the story of a whole people's struggle for freedom. From the very beginning until now. For we're still struggling. It's quite a story, York. How they all got together and set up a government. Whereby all men were pledged to defend the rights of each man, and each man to defend the rights of all men.
York is given leave to think things over. If he decides he still can't fight, the officer says he'll arrange for his conscientious objector exemption. York spends his leave reading the Bible and the History of the United States, and returns to the unit willing to fight, or at least to die.