When today’s historians look at the confrontation between the United States and North Korea, they’re likely to hear echoes of ultimatums, bluffs and botched messages that accompanied conflicts of the past, often with catastrophic consequences.

“The one thing that’s certain when you choose war as a policy is that you don’t know how it will end,” says Mark Stoler, a diplomatic and military historian at the University of Vermont. This fog of uncertainty should be a caution for policymakers now in dealing with North Korea.

History teaches that wars often result from bellicose rhetoric and bad information. Sometimes leaders fail to act strongly enough to deter aggression, as at Munich in 1938. But more often, as in August 1914, conflict results from a cascade of errors that produces an outcome that no one would have wanted.

World War I is probably the clearest example of how miscalculation can produce a global disaster. As Stoler recounted to me in an interview, each player was caught in “the cult of the offensive,” believing that his nation’s aims could be fulfilled in a short war, at relatively low cost.

It was a tragic sequence: After the assassination of Archduke Franz Ferdinand, Austria asked for Germany’s support against Serbia; Kaiser Wilhelm foolishly offered a “blank check.” Russia, Serbia’s ally, began mobilizing forces; Germany countered with its own mobilization, as did France, and then Britain. ...