By canceling his summit with North Korean leader Kim Jong-un, President Donald Trump has proved his lack of skill as a negotiator, handed the world’s most brutal dictator a win, and further isolated the United States as a world power.

In a letter to Kim, released at the same time as Western reporters were witnessing the destruction of North Korea’s nuclear test site, Trump wrote that proceeding with a summit would be “inappropriate,” given the “tremendous anger and open hostility” in Kim’s recent statements. He thus revealed how little he knows about the history of diplomacy with Pyongyang—a true expert could have told him that fiery rhetoric is par for the course—and about Kim’s long-standing position on the issues that were to be discussed.

The statements that threw Trump for a loop—issued by North Korea’s vice minister for foreign affairs, who has been its top negotiator for more than a decade—were, in substance, no different from Kim’s public position since the idea of a summit came up months ago: that the goal should be “denuclearization of the Korean Peninsula” (not just of North Korea), achieved, if at all, through “phased and synchronous measures” (not all at once).

Trump’s pullout is puzzling, in that, at his press conference this week with South Korean President Moon Jae-in, he said that, while he would prefer instant disarmament by Pyongyang (the position pushed by National Security Adviser John Bolton and Secretary of State Mike Pompeo), a phased approach might be acceptable.

Trump may think that Kim will now come crawling back to the table, but this is a dubious proposition. First, Kim’s negotiator had already threatened to pull out, saying that there was no point talking if Trump endorsed Bolton’s public comparison of North Korea to Libya, a country whose voluntary surrender of its nuclear program led to a Western-backed ouster of its leader, followed by his brutal murder.

Second, Kim doesn’t need this summit. He has already, deceptively or not, cultivated the image of a peace-seeker, through a charm offensive that began with his New Year’s Day message and continued through the Winter Olympics, his own summits in China and South Korea (the first meetings with those countries’ leaders on their territory), his offer to meet with Trump, his suspension of nuclear and missile tests (though only after announcing that he now had a viable nuclear arsenal), and proposing “denuclearization” (though with a vague timetable and the usual caveats).

Imagine if Trump had gone ahead with the summit, which was scheduled for June 12 in Singapore, and Kim hadn’t shown up, still protesting Bolton’s remarks. Trump could have touted himself as the real peace-seeker. He could have invited the leaders of South Korea, Japan, and perhaps China to come along and, in lieu of the scheduled summit, held a security conference, to discuss further steps to contain and isolate Kim’s regime. It would have been a double win for Trump.

No doubt Bolton and Pompeo are relieved, and may have prompted, Trump’s cancellation. They never wanted a summit to begin with. Bolton had said, as a guest on Fox News before he was hired by Trump, that he hoped the summit would end badly and quickly, so Washington could proceed with ousting Kim’s regime by force if necessary. Bolton had also written op-eds arguing that a preventive strike against North Korea was legal and necessary.

Trump’s big mistake was accepting Kim’s invitation to a summit without first discussing its potential risks and opportunities with people who know something about these things. His second, bigger mistake was hyping expectations, tweeting that a peace treaty was on the horizon and that he should win the Nobel Peace Prize simply for agreeing to meet. These absurd remarks only heightened his own stake in the summit’s success—and Kim’s leverage in the negotiations.

Many observers, especially in Japan, may have heaved a sigh of relief Thursday morning, as they feared that Trump was so eager for a deal that he might accept a bad one.

Now what happens? Trump cannot resume his “fire and fury” campaign to pressure Kim to disarm through military threats—at least as long as Kim continues to suspend tests and persuades his neighbors that, hey, he tried to make peace but these dangerous, unreasonable Americans backed off. Moon, who is very keen on promoting North-South détente, may now move toward a separate peace, independent of whatever Washington wants. Japanese Prime Minister Shinzo Abe, who fears both Pyongyang’s aggression and Trump’s isolationism, may feel compelled to find his own way through the shoals as well, possibly building his own nuclear deterrent. Chinese President Xi Jinping, whose relations with Trump had begun to fray, may have mixed feelings—pleased at the shrinking of U.S. influence in the region, nervous about Kim’s ambitions, which he may have hoped the summit’s outcome would help contains

So it’s been quite the season in diplomacy for Trump, the self-glorified deal-maker. First, he pulled out of the Iran nuclear deal, which had been working quite well, thus alienating the United States from its European allies, whose leaders had co-signed the deal, and whom he is now also threatening with economic sanctions if they try to keep the deal going. Now he cancels a summit, which never had the slightest chance of producing the results he hoped for (North Korean disarmament, a peace treaty, and gobs of contracts for U.S. firms to turn the communist dictatorship into a capitalist paradise) but which could have resulted in modest, useful steps toward a relaxation of tensions.

What is Trump’s Plan B? As usual, he doesn’t have one.