After weeks layering flattery on Kim Jong Un, his North Korean bosom buddy, Donald Trump conceded that he’d failed to achieve a diplomatic breakthrough during their intimate colloquy in Hanoi, Vietnam. “Sometimes you have to walk, and this was just one of those times,” a deflated Trump said Thursday during a press conference that concluded his second high-profile summit with Kim. On the one hand, the impasse was unexpected. As his former personal attorney, Michael Cohen, testified back in Washington, D.C., Trump was surely hungry for a diplomatic victory—even an empty one. The White House was teasing a Cohen-obliterating newsbreak, too, telling reporters on Wednesday that a “joint agreement” between the two leaders was imminent.

But that agreement never came to fruition. Standing before a blue backdrop embellished with “Hanoi Summit” branding and flanked by an awkward-looking Mike Pompeo, Trump said he was unwilling to give the North Koreans what they wanted. In exchange for lifting the economic sanctions imposed on Pyongyang as part of the Trump administration’s “maximum pressure” campaign, Kim allegedly offered to shut down Yongbyon, a North Korean nuclear complex, but stopped short of making other concessions the U.S. asked for. “It was about the sanctions,” Trump explained. “Basically, they wanted the sanctions lifted, in their entirety, and we couldn’t do that. They were willing to denuke a large portion of the areas that we wanted, but we couldn’t give up all of the sanctions for that.”

Among diplomats, Trump’s decision to bail out was mostly a welcome development, given the empty, reality-TV-show spectacle of the first Trump-Kim summit. “I am pleased that our president walked away and ended the discussion, rather than cut a bad deal,” a former high-ranking State Department official who worked in the region told me. Others echoed the sentiment, with a crucial caveat. “If Trump's description of what happened at the summit is accurate, then he did the right thing,” Joel Wit, who was involved in prior negotiations with the North Koreans while at the State Department, wrote on Twitter.

Of course, Trump’s explanation may not have been entirely accurate. Hours later, North Korea’s foreign minister claimed that Pyongyang had offered to permanently dismantle its nuclear-materials production if the U.S. lifted 5 of 11 sets of sanctions, not all sanctions, as Trump seemed to suggest. And some North Korean experts expressed incredulity at the Trump administration’s reaction. “It is exactly what we thought their position was. The position is they do Yongbyon, and they get an easing of sanctions. I don’t understand how this came as a surprise to Trump and [Stephen] Biegun and Pompeo,” said Jeffrey Lewis, the director of the East Asia Nonproliferation Program at Middlebury. “How is this a surprise?”

“I thought it was amateur-hour diplomacy,” fumed the former State Department official, frustrated that the U.S. and D.P.R.K. hadn’t spent more time negotiating at lower levels before staging a second high-profile summit. “The president of the United States should not have to fly all the way around the world, [and] cross multiple time zones, only to learn that we really aren’t close to a deal. Wastes valuable time for an incredibly busy person.” En route to Manila, Secretary of State Pompeo defended the logic behind leaving the deal-making to Trump and Kim. But, the former official told me, Trump’s ad-hoc style also left the North Koreans with no incentive to talk to anybody else. The dispiriting result—another stalemate in which North Korea continues producing fissile material—“shows the flaw in having one-person diplomacy,” the official said.