Trump and Kim Jong-un are going to meet. Some thoughts:
1) If you are a dictator, build a nuke ASAP. Saddam and Qaddafi didn't or couldn't, and now they are dead. Kim Jong-un gets a face-to-face with the President. Trump will bluster and look to "win" the meeting but in fact, Kim and North Korea have already won. Bigly even.
2) The U.S. currently does not even have an ambassador to South Korea. At a time when a solid, consistent message is crucial, Trump with change his mind every damn minute and treat the meeting, as he does all things, as another episode of a reality show.
3) South Koreans aren't dummies. They realize Trump is a wildly inconsistent egomaniac. Bringing KJU's sister to Pyeongchang was a bold move (despite a petulant and childish Mike Pence) that led to this thaw.
4) Trump and Kim are both going to declare themselves victorious after the meeting.
5) The meeting will make very little difference towards long term peace on the Korean peninsula.
6) "Cautiously optimistic" is a cliche but hey, why not be cautiously optimistic? Maybe, just maybe, Kim is sincere in wanting to cool things down. And why not? He's basically already won (cf. point one).