Trump is going to have a summit with Vladimir Putin on July 16 in Finland.  I’m sure he’ll do the requisite sucking up to the boss that all good and loyal employees do.

In the past few weeks alone, Mr. Trump has called for Russia to be readmitted to the Group of 7 industrial powers, suggested it has a legitimate claim to Crimea because a lot of Russian speakers live there and continued sowing doubts about whether Moscow meddled in the 2016 presidential election — or if it did, whether the sabotage actually benefited Hillary Clinton.

In Singapore, Mr. Trump emerged from a lunch of sweet and sour crispy pork with Mr. Kim to declare he had solved the nuclear crisis with North Korea, even though the North conceded nothing on its weapons and missile programs. Mr. Trump also canceled joint military exercises with South Korea, a concession long sought by Pyongyang.

It has become a recurring motif for Mr. Trump as a statesman: In November, he lavished praise on President Xi Jinping of China after a one-on-one meeting in Beijing, during which Mr. Xi offered no concrete concession on trade — an issue that matters more to Mr. Trump than almost any other.

What these three leaders have in common is that they are autocrats, whom Mr. Trump admires and believes he can win over with a brand of personal diplomacy that dispenses with briefing papers or talking points and relies instead on a combination of flattery, cajolery and improvisation.

“Trump sees a good meeting as a positive diplomatic achievement,” said Michael McFaul, a former American ambassador to Moscow. “That’s wrong. Good meetings are a means to an end.”