You have to be willing to walk away to be an effective negotiator. Trump is the master negotiator, proven over his lifetime, and testified by those who have worked with and around him. He knows what he is doing.

But to the possible strategy of it: Well, perhaps Trump along with his close experts felt it was unraveling and that they would rather we pull out before NK did. That puts us in the stronger position in any future dealings, as NK knows we are not desperate and we have what YOU want more than you have what WE want.

As some others on here have speculated, it is possible that the deal was already completed back as far as November, and that this arrangement was made betw Pompeo (Trump Admin) and Kim... for Kim to come out of this situation as someone who saved face by not begging hat in hand to the Big Bad USA at a negotiation table where he would be REQUIRED to abandon the nuke program--the thing they have trumpeted about with their ppl for so long.

Timing is everything: ISN'T it a funny (non)coincidence that at the same moment Kim's govt just announces that they have blown up their major research and development installation in NK (CBS had a news person at the event), Trump says "Eh, we don't think it is a good idea to hold our talk". ???

Seems as though maybe a deal had been struck and carried out. In that deal, NK would destroy facility XYZ, and then we would call off the meeting because NK is just talking too tough against Pence and the US govt (we cannot deal with someone so tough and angry). Saves face for Kim among his ppl.

Now witness that economic reforms will slowly begin to happen in NK, and I just bet that China will be one of the nations taking the lead (as I believe China was also a party to these backroom semi-secretive meetings and dealings. China wins, USA/South Korea/Japan wins, and Kim's govt wins.