President Trump’s letter canceling his June 12 summit with North Korea’s Kim Jong Un is a coy piece of manipulation — flattering and threatening Kim at the same time. It’s like the letters people send when breaking up a romance that hasn’t quite ripened. The words seem heartfelt, even as they stick in the knife.

“l was very much looking forward to being there with you,” Trump writes in the tone of a wounded suitor. “Sadly, based on the tremendous anger and open hostility displayed in your most recent statement, I feel it is inappropriate, at this time, to have this long-planned meeting.”

And then the sober warning, responding to North Korea’s taunting challenge this week to “meet us at a meeting room or encounter us at a nuclear-to-nuclear showdown.” Answered Trump: “You talk about nuclear capabilities, but ours are so massive and powerful that I pray to God they will never have to be used.”

On balance, Trump may have been wise to back away from a meeting that he had seemed in recent weeks to want too much and to have prepared for too little — and to let Kim think for a while about the “great prosperity and wealth” he’s giving up in retaining his nuclear weapons. But Trump, as usual, has chosen a risky course. His letter could produce a renewed confrontation that would be damaging for U.S. relations with South Korea and China, in addition to resuming the brinksmanship with Pyongyang.

“This opens the door for Kim to play a much more complicated and nuanced game than we had wanted. We’ve dealt ourselves out,” warns Robert Carlin, a former CIA and State Department analyst who has visited Pyongyang more than 30 times.

The jilt letter was cunningly timed, allowing Trump to pocket some of Kim’s concessions without giving anything in return. North Korea had a few hours earlier destroyed some of its nuclear test sites. And two weeks ago, Kim had released three American hostages, in what Trump Thursday called “a beautiful gesture” that “was very much appreciated.”

Trump’s open rebuke is a loss of face for Kim. That may be intentional, but as so often with Trump, the disruptive move will have its costs. Notes Carlin: “The letter is a direct challenge. Why did this have to be released publicly?”

One risk is that Kim will revert to his former belligerence, even resuming his missile and nuclear tests. That would be bad news for everyone. The summit and its de-escalation of tensions had been welcome partly because the U.S. has few good military options if the confrontation escalates.

South Korea’s reaction is another wild card for Trump. The pre-summit diplomacy was managed by President Moon Jae-in and his intelligence advisers. And just two days before Trump’s abrupt withdrawal, Moon had been in Washington arguing for diplomacy.

South Korea faces a series of question marks. Will the North-South amity that culminated in the April 28 summit at Panmunjon continue? Or will Moon loyally follow Trump, even at the cost of heightened tension on the Korean peninsula? It’s almost certain that Kim would try to exploit new friction between Seoul and Washington.

Future U.S.-South Korean military exercises, always a sore subject for the North, will be an especially delicate issue now. A few days ago, the betting would have been that upcoming joint maneuvers would be scaled back in a post-summit “Spirit of Singapore.” Now, they may be a flashpoint.

On the road to Trump’s break-up letter, both sides seem to have realized that they were heading to Singapore with unrealistic expectations. For Kim, the pointed reference to the “Libya option” by National Security Adviser John Bolton last weekend (seemingly withdrawn by Trump and then reiterated by Vice President Mike Pence) was surely a jolt. The message Kim seems to have taken was that his entire nuclear stockpile (and maybe his regime, and his very life) were at risk.

North Korea’s defiant statements over the past week told Trump that Singapore wouldn’t be a walkover; the mesmerizing chants of “Nobel Prize” had perhaps obscured the wide gaps in position. Those problems were highlighted when North Korea skipped a preparation session, and the two sides couldn’t craft the frame of a summit communique.

Trump thinks the prospect of American investment may draw Kim back to the table. But it’s just as likely that the nimble Kim will decide he has escaped a trap. If he wants modernization, China may be a more reliable bet.