Eh, if I knew how to do that, I would be a household name worldwide, not shitposting on Lemmy.
That being said, I think the most likely course of action to prevent conflict is to make individual people uninterested in conflict. Most people already aren't. Soldiers need to specifically be trained to kill, because that's not something the majority of people want to do.
If the general says "fight!" And the foot soldier says "no, I think I'd like a nap", does the war happen?