Is the world getting more peaceful? Some academics think so. New research, though, suggests they might be getting their math wrong.
Since 1945, armed conflicts between great powers have become much less frequent, and the annual number of fatalities has consistently declined. This has led some people — among them the noted psychologist Steven Pinker, in his book "The Better Angels of Our Nature" — to suggest that humanity may, perhaps, be growing out of war and moving into a more peaceful era. It's an idea that military historians find intriguing, and quite plausible.
Unfortunately, it may also be wishful thinking. Getting statistics right is hard, and it's especially hard when dealing with wars, which — like earthquakes and financial markets — follow a highly erratic pattern.