Which brings us to North Korea. The typical Trump "negotiation" is simply a way of playing the odds. You lose a few, win a few, and intimidate the rest, just like his mentor Roy Cohn taught him.
But what happens when the negotiation is existential, and losing is not, shall we say, a viable option? If you're playing poker with somebody sitting on satchel charge of C-4 with a dead-man switch in his hand, it's not really smart to play to an inside straight. You have to be right every time, and you can't make empty bluffs. The entire Trump negotiating strategy is structured around the empty bluff. Normally he only needs to win enough times to break slightly ahead of even.
But this is not a normal situation. Kim is not going to back down, nor will he be fooled by any bluff. He will absolutely force Trump's hand. And Trump is not sitting on a winning hand.
Trump loses under most conceivable outcomes. Not hard to game it out:
1) Kim is cowed by the majesty of Trump's rhetoric, and slinks back into his underground lair. I'll let you assign a probability to that one. At any rate, this leaves the situation basically unchanged. Kim 0, Trump 0
2) Four missiles head to Guam. The US military manages to shoot down between 0 and 4 of those missiles. If any of them survive, the powerlessness of US missile defense will be exposed. Kim 1, Trump 0. If all 4 are shot down, Kim 0, Trump 1...at least for that round.
3) Trump orders a pre-empitve non-nuclear strike. This would be catastrophic for all sides. The US could not destroy all of Kim's artillery in time to prevent the near destruction of Seoul (45 second flight time for artillery shells). At a minimum, tens of thousands of Koreans would die, and thousands of US soldiers, right from the get-go.
The US could prevail eventually, assuming the Chinese do not intervene (this is far from guaranteed). If Kim knows he is going down, the likelihood of a nuclear explosion over Seoul is very high.
This would be the end of the US-South Korean alliance. The US would be blamed by the vast majority of Koreans, and Americans would be pariahs both sides of the 38th parallel.
4) US uses pre-empitve nukes to decapitate NK, and wipe out its artillery emplacements and forward troop concentrations. Again, tens of thousands of Koreans would die. The end of the US-SK alliance is assured.
5) Trump tries to buffalo NK by moving carrier groups, subs, and missile ships into the area. It won't work. NK won't back down short of actual massive force. The end result would only be to demonstrate the impotence of US force projection.
There are endless variations of these outcomes. They all have in common a precipitous decline in US power. Any actual shooting war that was not obviously set in motion by a NK attack would lead to a quick collapse of Asian security arrangements. Virtually overnight. You will see SK, Japan, Australia, and Singapore cut loose from the US. Public opinion in Europe would destroy NATO as a significant force. This is effectively the end of the American Empire.
I have no problem with the end of the American Empire per se, but the actual cost in terms of human life is steep - unimaginably steep, if things go south. And the ways things could go south in this confrontation are distrubingly endless.
The most plausible catastrophic scenario is one of NK's nukes being use against SK, and the subsequent spread of nuclear warfare to major players. None of us can really quantify this risk. We have two unpredictable leaders known for brinksmanship and serious personality defects.
So maybe this eventually blows over. Maybe this is all worry for nothing. But Trump seems too much like a blind man waltzing into a minefield. Luck is what we need, and the US military keeping a short leash on the bumbler-in-chief.