[link to www.sciencemag.org]

"Clauset found the unimaginable carnage of World War II was not, in fact, a statistical anomaly; its death toll falls well within the expected range for war deaths.
...
there’s nothing special about the current 'long peace,' Clauset reports today in Science Advances. In order for our present peaceful era to become meaningfully aberrant—that is, for it to represent a real change in our ability to get along—it would have to last for another 100 to 140 years."