Crystal ball says

So, at this moment, Donald Trump and Kim Jong-Un are having their historic meeting. The world holds its breath.

Spoiler: it's going to be a big success. DJT will emerge and tweet triumphantly about his "HISTORIC agreement that NO OTHER PRESIDENT managed, Kim is a very reasonable guy who just wants to be left alone." Because why wouldn't he? We already know he (consistently) gets along far better with despots than with elected politicians.

And, importantly, he hasn't taken any advisors to this talk - no-one who actually knows what a nuclear weapon or rocket looks like, much less how to inspect them. So they can't even discuss any actual inspection/enforcement regime. They both have nothing to lose by emerging and trumpeting their respective victories.

It won't be until after the midterms that it becomes obvious that the "agreement" had no actual content, it was nothing more than a handshake. Short-term effect: poll bump for Trump, quite possibly long-lived enough to see his party through the midterms. All the people who might have tried to pour cold water on the HISTORIC AGREEMENT are conveniently cowed (other Republicans who know what they're talking about), replaced with Trump toadies (the CIA), discredited (Democrats, the press), or simply silenced (McCain). Long-term effect: nil.

Enjoy the spectacle. Here's the president of the richest and most powerful country on earth, sucking up to a dictator who makes Charlie Chaplin look statesmanlike. He's eliminating a supposed threat to the mightiest military the world has ever seen, posed by a country with the GDP of Wiltshire. All it really needs is Peter Sellers, and the world would recognise it for the comedy it is.