This week we attempt to watch Ken Burns’ epic ten-part Vietnam documentary, and allow ourselves to get extremely depressed at the futility of war while asking: Is there some sense in which we need war? Are Americans, in particular, fond of the notion of “holy war”? Can there ever be a purely “secular war”? Is America headed for another Civil War? We interview Dr. James Byrd, professor of American religious history at Vanderbilt Divinity School, on the religious imagery of...