People all the time fight in wars without having the slightest idea what the war is about. Read, some time, Tim O'Brien's explanation of why he fought in Vietnam. In The Things They Carry. On the radio, immediately after 9/11, there was an interview with a Native American who was rushing out to join up. When asked what he thought about the war, he said he thought it was B... S..., but that he was a warrior. Or Steven Vincent Benet's book on the Civil War, where an Appalachian settler was rushing off to join the Confederate Army. Someone asked who was the enemy, and he answered "I don't know. They call them 'Yankees,' but they aren't Indians."