I think this underestimates the North Korean approach. The past year has been provocation to see what we'd do and from a clear-eyed foreign policy perspective, the answer has been "nothing." North Korea then met with South Korea without any involvement from us - I think that's a new thing under the sun, too.
I've been thinking about this comment all weekend, and I think I know what I don't like about it, and I italicized it.
With Trump's general abdication of all foreign policy positions that the US has lead for the last 50 years, South Korea saw that they were no longer beholden to the US's terms of engagement, and that if anything were going to happen, they had to take the lead.
The Olympics were the perfect opportunity to step out of the US's shadow, and become the Lead Negotiator in driving a new relationship with NK and KJU.
Countries are no longer burdened by worrying about what the US may think about their actions, and how we may interpret their efforts, diplomatically, because our diplomatic corps has been decimated, and Trump has no understanding of the world markets or political scene. He also has no more advisors on staff who have any understanding of the world outside of a narrow, 200-mile wide band, extending from about W 148th in Manhattan in the north, to Norfolk, VA in the south. (Mar a Lago is obviously on an island somewhere in the Caribbean, to these people.)
Trump has effectively eliminated the US's "soft power", world-wide, and SK's direct conciliatory moves towards NK are proof positive of that.
If Clinton were President, this could not have happened. Diplomats would have talked back-channel, and NK would have been consistently shitty about their failure to adhere to the terms of any prior agreements, and the diplomats would have been forced to say, "Sorry. No talks with the Prez, then. You are clearly not interested in reaching a deal, because you have already failed to live up to your previous commitments, so why should we open talks with you again? You are just going to lie again."
And ... wait ... did I just argue that the diplomacy we have practiced ever since the end of WWII is no longer relevant today, and we should just start with a clean slate with all the Bad Actors in the world, and try again with their new management?!?
That would mean I think that - in the long run - Trump did something good.
I'ma gonna have to go sit with that uncomfortable thought for a bit... eeewwwww ....