It took tens of millions of dead to create the relative peace of the later 20th century, that is a hell of a rock bottom. We got the UN, nuclear Non-Proliferation Treaty, war crimes treaties, free trade, unprecedented prosperity. It's humanity's greatest achievement but we're throwing it all away. Partly due to attacks from monied interests and propagandists, partly to protect Israel (the 15th Crusade), partly because of hatred of peaceniks and bureaucrats, but largely because we've all forgotten the costly lessons.