Constantine's Sword (2007) on Netflix

Plot summary

James Carroll was a Catholic priest before he left the priesthood, and his father, Joseph Carroll, was an Air Force general. As a boy, Carroll asked his father what the letters IHS in churches meant, and the answer tied the name of Jesus to the sign Constantine saw in his vision. Carroll traces the roots of war to the Roman emperor Constantine I, who credited a vision of the cross with a battlefield victory in 312 AD. He charges that evangelicals in the United States military influence the country's foreign policy.