For years, a story circulated in Washington about Donald Trump’s attempt to nab a job leading nuclear negotiations with the Soviet Union in the nineteen-eighties. His book “The Art of the Deal” had been on the Times best-seller list for forty-eight weeks. Trump apparently thought that he could do a deal one-upping anybody—and wanted to prove it. He lobbied quite hard, I was told, with the George H. W. Bush Administration. The White House instead appointed Richard Burt, the U.S. Ambassador to West Germany during the run-up to the fall of the Berlin Wall and a longtime expert on nuclear-arms talks.

Shortly thereafter, by coincidence, Trump and Burt attended the same society wedding in New York. At the reception, Trump walked up to Burt—whom he didn’t know—and said, “So you’re the guy?”

Burt, who confirmed the story to me, acknowledged his new position. Trump then said, “Let me tell you what I would have done if I’d been appointed.” He explained that he would have welcomed—very warmly—the Soviet delegation. He would have made sure the country’s envoys were comfortable—very comfortable—at the table.

Then, Trump told Burt, he would have stood up, shouted “Fuck you!,” and left the room. (The White House did not respond to a request for comment.)

This month, I chatted with Burt about what that story says about how Trump, a real-estate magnate who has been in office only fourteen months, might deal with Kim Jong Un, the third leader in a seventy-year-old dynasty, during the President’s first stab at real nuclear diplomacy. North Korea has at least twenty nuclear bombs—atomic and hydrogen—as well as ballistic missiles now capable of hitting any part of the United States.

“I don’t know if it has implications for nuclear issues in particular,” Burt, a Republican who contributed ideas to Trump during the early days of his candidacy, told me. “It just says a lot more about the guy’s approach to negotiations. Trump loves the chaos and the bluster—and to mouth off and get people off balance. He wants to destabilize them, get them out of their comfort zone, then try to dictate the terms. By doing that, he believes he can get the upper hand. It’s the triumph of technique over substance.”

President Trump is already boasting about his success in negotiating with North Korea, even before a date for talks has been set. On Wednesday, he tweeted about it yet again: “For years and through many administrations, everyone said that peace and the denuclearization of the Korean Peninsula was not even a small possibility. Now there is a good chance that Kim Jong Un will do what is right for his people and for humanity. Look forward to our meeting!”

Trump’s conceit notwithstanding, deep concern permeates Washington about whether the President has the patience or policy sophistication to broker one of the most complex arms deals—with one of the quirkiest U.S. adversaries—in modern history. Trump may be twice as old as the North Korean leader, but he has so far failed to demonstrate much diplomatic technique as President.

Other more experienced Presidents have also failed at pivotal summits on nuclear issues, however. In 1961, President Kennedy’s summit with Soviet Premier Nikita Khrushchev, in Vienna, tanked. Kennedy had proposed the summit, after the Bay of Pigs fiasco in Cuba, to “exchange views.” On a stop in Paris first, the French President, Charles de Gaulle, warned Kennedy that he might not be able to match wits with the Russian. He was right. “Kennedy believed he could charm the guy, and he failed miserably,” Burt said. “He wasn’t adequately prepared and thought he’d fake it and succeed—but didn’t.”

Khrushchev had the upper hand throughout the two-day negotiations. At one point, he went on a famous tirade. During a lunchtime stroll, a Kennedy aide later recounted, the stocky Russian leader was “snapping at [Kennedy] like a terrier and shaking his finger.”

“I never met a man like this,” Kennedy told Time. “I talked about how a nuclear exchange would kill seventy million people in ten minutes, and he just looked at me as if to say, ‘So what?’ ”

In 1986, President Reagan’s summit with the Soviet leader, Mikhail Gorbachev—at a whitewashed mansion in Reykjavik, Iceland, halfway between Washington and Moscow—was supposed to explore ways that the two superpowers could limit their nuclear arsenals. The two-day talks were stressful. The two leaders came close to a deal. But, in the end, they failed to produce anything tangible, mainly because of Reagan’s refusal to compromise on the space-based missile-defense system known as the Strategic Defense Initiative, or, colloquially, “Star Wars.”

“The United States was not prepared for that meeting,” Burt reflected. “Gorbachev came prepared, but Reagan didn’t.”

Burt argued that a better model for the Trump-Kim summit is the methodical diplomacy that took place between the United States and China in the early nineteen-seventies, when Secretary of State Henry Kissinger and Premier Zhou Enlai laid the groundwork for a summit between President Nixon and Chairman Mao Zedong. The subsequent detailed Shanghai Communiqué laid out specifics to normalize relations, covering many issues over many years.

“Real discipline went before that,” Burt told me. The new U.S.-North Korea diplomacy has the potential, he said, to be “as big as the opening to China.”

In any deal, however, the United States will want to put in place an elaborate verification program to insure that North Korea “denuclearizes”—and that the U.S. can track its further armament programs. For North Korea, in turn, the issues extend well beyond its nuclear program. To surrender its bombs and ballistic missiles, Pyongyang will want—at a minimum—an armistice and peace treaty to formally end the Korean War, which was officially halted, in 1953, only by a truce. It will almost certainly seek normalization of relations, the withdrawal of U.S. troops from the Korean Peninsula, and an end to U.S.-South Korean military exercises, as well as economic aid and the end to punishing sanctions that have crippled the economy.

“This requires an enormous amount of creativity and great historical understanding,” Burt told me. “Trump doesn’t have that kind of patience. That’s way more than these guys can do. Trump thinks he’ll get through this with bombast and pressure, rather than mastering the details. I don’t know anything about Kim. But he’s not an idiot. If he does his homework, this could go very badly for Trump.”

As Trump prepares for the summit, the Administration’s diplomatic bench is also shallow, with key positions—including the ambassadorship to South Korea—still unfilled and Joseph Yun, the U.S. special representative for North Korea policy at the State Department, retiring this month.

When Burt was appointed, in 1989, as lead negotiator with the Soviets, he was building on a proposal first made by President Reagan in 1982—and on an idea dating back to the ninety-sixties. “By the time I started, we had a vocabulary, a discipline,” he told me. “We stood on the shoulders of giants who started this in the late sixties. It took a lot of time and trouble to create this whole process. We drew on a generation of experience and expertise.”

Burt’s team required another two years to conclude the Strategic Arms Reduction Treaty, or START, one of the largest and most complex arms deals in history.

Trump has less than two months to plan for his summit with Kim.