August 8, 2017:

“North Korea best not make any more threats to the United States,” Trump told reporters from his Bedminster, New Jersey golf course, where he is vacationing for the next two weeks. “They will be met with fire and fury like the world has never seen. They will be met with fire, fury, and frankly power the likes of which the world has never seen.”

President Donald Trump on Tuesday warned North Korea against escalating nuclear tensions, promising the United States would unleash unprecedented “fire and fury” if the country did not stop threatening to retaliate against the United Nations’ newest sanctions.

December 26, 2016:

Jeffrey Lewis, a nuclear non-proliferation expert at the Middlebury Institute of International Studies, points out that in peacetime, any belligerent Trump Tweet about nuclear weapons might not appear as alarming, simply because “confirmation bias” might lead key actors not to interpret it in its most frightening light at that moment. Amid rising international tensions, though, that confirmation bias might work in the other direction, he says.

“Imagine we’re in a crisis—if he recklessly Tweets, people could read these things in the worst possible light,” Lewis tells me. “The North Koreans have a plan to use nuclear weapons very early in a conflict. They’re not going to wait around. If they think we are going, they’re going to use nuclear weapons against South Korea and Japan.”

…

As a potential example, Lewis points out that earlier this year, Trump said he would handle the North Korean nuclear threat by getting China to make North Korean leader Kim Jong Un “disappear.” Lewis notes that imprecise language in an errant, bellicose Trump Tweet — particularly amid rising tensions — could conceivably amount to an “accidental assassination threat.”

“Imagine if the North Koreans are looking for any signs that we’re about to attack as their signal that they have to go,” says Lewis, adding that if Trump “says the wrong thing” and “gives the impression that we’re about to act,” the North Koreans might “decide not to wait around to find out if that’s true or not,” and might hit “targets throughout South Korea and Japan where U.S. military forces are stationed.”

In this telling, Lewis notes, it’s possible to envision some kind of ambiguous Tweet — such as, “we’ve gotta get rid of this guy” — unleashing untold consequences. Alternatively, Lewis argues, it’s possible to envision a rash Trump Tweet locking the U.S. into an untenable position by “closing off the president’s ability to back down or compromise,” rather than preserving maneuvering room, making peaceful resolution harder.