Shortly after the success of The Art of the Deal (1987) made Donald Trump a supposed expert on negotiation, he lobbied the George H.W. Bush administration to put him in charge of arms reduction talks with the Soviet Union. The position went instead to Richard Burt, an experienced diplomat and arms control expert. When the two men met at a New York social event, Trump pulled Burt aside to tell him what he would have done—and what Burt should do—to start off the negotiations. Greet the Soviets warmly, he said. Let the delegation get seated and open their papers. Then stand up, put your knuckles on the table, lean over, say “Fuck you,” and walk out of the room.

When I heard this story from Burt in 2016, it seemed further—if especially bizarre—evidence of Trump’s conviction that bluster and intimidation are universally effective. His interactions with North Korea over the past year, however, make clear that it’s more complicated than that. Trump thinks that what works is the unexpected. His goal is to put people off balance, which allows him, he believes, to get his way. This explains his otherwise baffling calls for US policy to be “unpredictable.” With North Korean leader Kim Jong-un, the unexpected came in the form of Trump’s claim to have fallen “in love” and his showers of praise for Kim’s personality, his intelligence, his talents, his love of his people, and his leadership—all for a man who runs the poorest economy in all of Asia and the beastliest regime on the planet.

To lavish this acclaim on Kim, Trump had to ignore Pyongyang’s record of cruelty, vast prison camps, hostage-taking of Americans, and assassinations. But the unexpected hasn’t worked any more than Trump’s ludicrous strategy would have worked with the Soviets. The reason is not hard to find. Two years in the Oval Office have had no effect on his conviction that the presidency is about himself, whereas the foreign leaders he meets are looking out for their national interests.

What happened at the second Trump–Kim meeting in Hanoi in late February had its roots in last June’s summit in Singapore. In March 2018 Trump leapt to accept a North Korean invitation to meet that envisioned “complete denuclearization of the Korean Peninsula.” He did not stop to learn that this language was not a breakthrough response to his threats of “fire and fury” but rather a phrase Pyongyang has used for more than twenty-five years—beginning with a North–South Korean agreement in 1992—to mean something drastically different from what Americans mean by it. By putting the emphasis on the Korean peninsula rather than just North Korea, Pyongyang means that it would denuclearize after the US signs a peace treaty formally ending the Korean War, ends its defense alliance with South Korea,…