Here's a good one. First one in my old Book of Quotations: "War is the science of destruction."
Pretty hard to top,eh? Think about it. As a rule, people all over the world pool their combined resources to make for themselves, family, friends and neigbours a better, pleasanter world through their work and service - and along comes some idiot who's willing to destroy all that just on an idea, an ideology, or simply envy and greed.
And, of course, there are always teenage boy soldiers and the immature who life hasn't touched yet, who will 'step up' for such people because they think going off to war is an adventure. Those who encourage them, of course, feel no shame.
Three hundred years to build a great city: three seconds to reduce it to rubble with an atomic bomb. My, we've come along way, haven't we?