War has been an integral part of human history for some 11,000 years or so, depending on the definition of war. Iconic anthropologist Margaret Mead wrote an essay in 1940 that declared that, like so many other human practices, war is an invention—we are not doomed to wage war simply because of human nature. She proved her hypothesis simply by describing peoples that not only didn’t ever wage war, but often didn’t even have a concept of what war is.