If there's one thing that was sure to be a part of the U.S.-North Korea summit this week, it was chemistry.
Chemistry is important to Donald Trump. It drives how he picks those he wants on his team and those he doesn't. It's also a tool he uses, a weaponized flattery that's common in business negotiations. But too often it's how he evaluates those negotiations. If the chemistry is good - meaning if you flatter him - you tend to get more of what you want.
“I would say personal rapport is probably more important with him than it would be with a more conventional president," one Western diplomat told The Guardian last month. "The idea that getting on with someone is what’s crucial to the outcome of the discussions wouldn’t normally be the way people see it. But he’s inclined to see it as a question of personal chemistry."
He's also inclined to make sure everyone knows how well he's getting along.
On Chinese president Xi Jinping: "We have a great chemistry together," Trump told the Wall Street Journal last April. "We like each other. I like him a lot. I think his wife is terrific."
On German chancellor Angela Merkel: "One of the best chemistries I had was with Merkel," Trump said last year after the two met.
On Japanese prime minister Shinzo Abe: "We have a very, very good bond — very, very good chemistry,” Trump said after a White House meeting last February. He also said Abe had "strong hands."
On Egyptian president Abdel Fatah al-Sissi: "People have given me credit for having great chemistry with all of the leaders, including al-Sissi."
And, of course, Trump mentioned a "positive chemistry" with Vladimir Putin after they shook hands at the G20 summit last year.
An exception: Trump apparently has not used the word "chemistry" to describe his relationship with French president Emmanuel Macron, but he didn't have to:
But the important thing to remember about Trump and chemistry - like Trump and lot of things - is that it's fleeting. Things have been on again/off again between Trump and Xi as they step toward and away from a trade war. Macron, Merkel and Abe are definitely on the outs right now. Relationships with Donald Trump have long been about what Trump can get out of them. So the president's assurances of "chemistry" this week with Kim Jong-Un? You can take that with a grain of NaCl.