Gutting your enemies with a rusty spoon!! AND BATHING IN THEIR BLOOD!!!revenge
Luckily Captain Kirk prevented the pacifist movement in WW2
I thought that was Patton. ;-P But seriously, it was brought down by a combination of factors, not a single person. Mostly, it was when people realised that you can't stop a Panzer or a Messerschmidt with prayers and dialogue.