I'd say Christianity has been the most successful large scale war restraining ideology. Not that it is perfect, but name a better large scale ideology.
OK. Civil rights.
Have two countries that grant full legal equality to both men and women ever gone to war?
But the argument in the grandparent post is not supported by history either. The military monk orders of the Crusades are just one example.
What? You're misinformed. Adams didn't believe that for one. A quote from the Treaty of Tripoli, ratified by the Senate in 1797 and signed by John Adams: "The government of the United States of America is not in any sense founded on the Christian Religion." The vote was unanimous, there was no public dissent, and Adams had the following to say about the treaty (emphasis mine): "I John Adams, President of the United States of America, having seen and considered the said Treaty do, by and with the advice and consent of the Senate, accept, ratify, and confirm the same, and every clause and article thereof."
I'm not trying to argue that Christian principles aren't present in our history (they are). But you're regurgitating a common talking point in an attempt to rewrite history.
Not only does Chritianity as a whole create yet another tribe for people to get divided by and fight over, it doesn't even enforce it's tribal rules (failing not killing, at least try to kill only the infidels) that well. Spanish history will attest to that. And even then it can manage to fracture itself and attempt to rip each other part into pieces.
I don't think the idea of 'but they're my brother in faith' ever really stopped someone from going to war when they realize 'hey, they just took my land'.