By the way

....We are a long way from conclusion on North Korea, maybe things will work out, and maybe they won’t - only time will tell....But the work I am doing now should have been done a long time ago!

— Donald J. Trump (@realDonaldTrump) April 22, 2018

Sensing a pattern here?

Trump told reporters at his Mar-a-Lago estate on Wednesday that, "if the meeting when I'm there isn't fruitful, I will respectfully leave the meeting."

A pattern?  Yes:

[U.S. Trade Representative Robert] Lighthizer is reportedly considering an aggressive plan that would force lawmakers to accept it anyway: withdrawing from NAFTA before the new version is ready. It’s a risky move, and one that experts say might turn out to be fruitless.

I don't see no pattern!

“The administration floated the idea of using the same tactic to gain leverage in the negotiations with Canada and Mexico — but ultimately decided it was better to work with those countries rather than threaten them,” Christopher Wilson, an expert on NAFTA at the Wilson Institute, told me.

“It would be strange and rather dangerous to employ hardball tactics deemed inappropriate for our trading partners on the Republican-led Congress,” Wilson added.

And then there's the Iran nuclear agreement:

Trump has said that unless European allies fix what he has called its “terrible flaws” by May 12, he will restore U.S. economic sanctions on Tehran, which would be a severe blow to the pact.

[French President Emmanuel] Macron, arriving in Washington for a state visit later on Monday, said on Sunday there was no “Plan B” for keeping a lid on Tehran’s nuclear ambitions.

Pretty much like there's no "Plan B" for a summit one of the participants simply walks away from, respectfully or not.  But Trump thinks this is how you negotiate.  Trump is the Deal Master!  You want to deal with him, you take his deal or he walks away!

And especially in this case, who loses?  Well, it won't affect Trump's pocketbook; and that's the problem:

Trump doesn't fulminate about North Korea or building a wall on the Mexican border because he's a policy maven with deeply held principles. It's because he knows that toying around with sensitive and sometimes dangerous subjects gets the media's attention and keeps certain blocs of voters interested in him.

Or, to put it in the terms David Cay Johnston used:

The 44 previous presidents were all over the map. There were smart people and dumb people, there were people of impeccable integrity such as Barack Obama and Jimmy Carter, there were absolute scoundrels like Warren G. Harding. We had a murderous racist in the White House whose painting hangs in the Oval Office now looking down on Trump. What distinguishes all those presidents, particularly Chester B. Arthur, the one closest to Trump, is that they tried in the context of their times to make America better.

Donald Trump is a man with this desperate need for adoration. He is an empty vessel, the exact opposite of Henry David Thoreau — a “life unexamined.” His only philosophy is the glorification of Donald.

Over the weekend, all the living  former Presidents except Jimmy Carter gathered in Houston for the funeral of a former First Lady who was also the mother of a President. Trump played golf and fumed on Twitter about James Comey and Chuck Todd.  Yeah, the pattern here is not a pretty one.