Mr. Trump’s initiative was widely praised, at first. After a quarter-century of fruitless negotiations at lower levels, a president-to-president summit seemed refreshing. But while the meeting had fabulous theatrics, the specifics were missing and the agreement was ridden with ambiguity and loopholes.
So when Secretary of State Mike Pompeo sought to obtain a list of the North’s nuclear facilities as a first step toward turning over weapons, Mr. Kim accused Mr. Pompeo of seeking a “target list” for American missile attacks. “I don’t need a target list,” Mr. Pompeo responded, making clear he already had one. He wanted to make sure, he said, that the North was coming clean.
The list never arrived. Subsequent talks quickly stalled over how to enforce a vaguely worded agreement.
In his New Year’s speech in January 2019, Mr. Kim threatened to find a “new way” if Washington persisted with sanctions. When Mr. Kim and Mr. Trump met in Hanoi the next month, their talks collapsed over differences over when to ease sanctions, and the North’s insistence that in return it would dismantle only its aging nuclear site at Yongbyon. That would have left him with other major nuclear sites, and all his missile launching capability.
Since then, North Korea has shifted gears, expressing anger and frustration with Washington and Seoul. President Moon Jae-in of South Korea made his own visit to the North, encouraged by both Mr. Kim and Mr. Trump, telling them that they were a once-in-a-lifetime pair to negotiate a history-making deal.
“Kim Jong-un’s expectations for his meetings with Trump were big,” said Lee Byong-chul, a North Korea expert at Kyungnam University’s Institute for Far Eastern Studies in Seoul. “So was his frustration when the talks collapsed.”
In May 2019, North Korea broke an 18-month hiatus in weapons tests, launching a series of mostly short-range ballistic missiles and rockets. Negotiators from both countries met in Stockholm in October but parted ways only confirming their differences. Later, North Korea said it was no longer interested in “sickening negotiations” with the United States. In December, it conducted two ground tests at its missile-engine test site to bolster what it called its “nuclear deterrent.”