Warfare probably peaked about the time of the Romans. It was bad enough that philosophies like Buddhism and Stoicism arose to cope with it. There was a philosophy though that arose to prevent warfare. It probably originated with the Zoroastrians but got traction later from a philosopher in the Middle East who taught, counterintuitively, to forgive and to love one another. It is how humans overcame their endless wars (whether it looks like it or not). He's sort of obscure though. I doubt you have ever heard of him. I think he was called Jesus.