The last few decades have been the most peaceful era in human history. For the first time ever, fewer people die today from human violence than from traffic accidents, obesity or even suicide. Whereas in early agricultural societies human violence caused up to 15% of all human deaths, and in the twentieth century it caused 5%, today it is responsible for only about 1%. Yet the international climate is rapidly deteriorating; warmongering is back in vogue, and military expenditure is ballooning. Both laypeople and experts fear that just as in 1914 the murder of an Austrian archduke sparked the First World War, in 2017 some incident in the Syrian Desert or an unwise move in the Korean Peninsula might ignite a global conflict.
Yet there are several key differences between 2017 and 1914. Back then, war had great appeal to elites across the world because they had concrete examples for how successful wars contribute to economic success and political power. Now, successful wars seem to be an endangered species.
From the days of Assyria and Rome, great empires were usually built through war, and elites in 1914 had plenty of recent examples for the huge profits a successful war can bring. In 1846–48 the United States invaded Mexico, and for the price of 13,000 dead American soldiers, it got California, Nevada, Utah, Arizona, New Mexico and parts of Colorado, Kansas, Wyoming and Oklahoma. It was the bargain of the millennium. Similarly, imperial Japan cherished its victories over China and Russia; Germany glorified its triumph over France; and almost every great power had a string of splendid little colonial wars to its name. When France, Britain or Italy contemplated putting boots on the ground in Vietnam, Nigeria or Libya, their main fear was that somebody else might get there first.