I am not denying original sin. I believe Jesus's teachings were pacifist. He went like a Lamb to the slaughter, as did the apostles. Father, forgive them for they know not what they do. So I would say even self-defense is questionable but I agree that if there are children, women or more vulnerable then we are called to self-defense. So while there may be some battles required, a longer term strategy of war seems inexcuseable. If the other warring party persists indefinitely then withdrawal and giving up ones property would be required. I think Pope Francis got it right on the death penalty. In the Old Testament such things were necessary. Now, as St. Paul says we must let go of the old-man and put on the new-man, the mind of Christ.