On the eve of his White House meeting with South Korean President Moon Jae-in, which is itself a prelude to his summit next month with North Korean leader Kim Jong-un, it’s worth recalling President Trump’s first stab at global diplomacy.

The event took place around 1990, at a reception in New York, where Trump met Richard Burt, who had just been named President George H.W. Bush’s chief negotiator at the U.S.-Soviet Strategic Arms Reduction Talks. Trump had wanted the slot himself—even lobbied for it avidly, to the shock and mirth of many—when the talks began under President Reagan. Now, meeting the man who got the job, Trump told him how to get a “terrific” deal: Arrive late at your first session; walk up to your Russian counterpart, who will have been sitting impatiently; look down at him, stick your finger in his chest, and say, “Fuck you!”

(Bruce Blair first reported this story in Politico in June 2016. Burt confirmed it to me early this month.)

Burt, a former senior State Department official, managed eventually to wrest a treaty, which cut both sides’ nuclear arsenals by more than one-third, without taking Trump’s advice. Could Trump, whose self-confidence in a setting seems proportional to his cluelessness, believe that some similarly brash tactic might work with Kim?

Trump is sleepwalking into a potentially historic summit with a determined leader who knows what he has and, more importantly, what he wants.

If he once thought so, his sheen of certainty now seems to be eroding. According to the Washington Post, Trump held an under-30-minute phone conversation with Moon on Saturday night—feeling the chat couldn’t wait till their meeting in Washington just three days later—to discuss the unexpected twist in the pre-summit politics with Kim. Monday’s New York Times confirms the report and adds that Trump and his aides are panicked that Kim doesn’t seem as eager as they thought he’d be to make a swift trade of his nuclear weapons for vague promises of economic assistance.

These aides are also, just now it seems, getting nervous about the fact that their boss has declined to be briefed on the summit’s issues, preferring to trust his instincts, while Kim—according to U.S. officials who have met with him—is well-versed on the most intricate details of his arsenal and the surrounding geopolitics.

No one should have been surprised by Kim’s refusal to give away his sole strategic asset. What put Trump into a tizzy was the Wednesday statement by North Korea’s top negotiator, stating that Pyongyang was not interested in the “Libya model” of disarmament (which Trump’s national security adviser John Bolton had publicly proposed) and that the summit, scheduled for June 12 in Singapore, wasn’t worth holding unless Washington agreed that the goal should be “denuclearization of the Korean Peninsula” (not just of North Korea), achieved by “phased, synchronous measures” (not all at once or with North Korea making its move first, as Trump and his advisers have demanded). This has been Kim’s position all along, and, by the standards of arms-control accords struck over the decades by other countries, including the United States, it’s quite reasonable.

Nor should Kim’s firm grasp of the issues have come as a shock. Though he’s young and a barbaric dictator, he’s no idiot; he’s been out in the world, having been educated at a Swiss boarding school; he has been the driving force behind his country’s success in assembling a nuclear arsenal. And when it comes to nuclear weapons, studiousness is a family tradition. When his father, Kim Jong-il, met with President Clinton’s secretary of state, Madeleine Albright, in 2000, to hammer out a possible treaty to bar North Korea from building ballistic missiles, Albright’s staff members—who attended the meeting—were stunned that Kim had mastered every detail and could discuss them without consulting his own aides. (Clinton’s term ended before a deal could be reached; George W. Bush had no interest in resuming where Albright left off.)

In short, Trump is sleepwalking into a potentially historic summit with a determined leader who knows what he has and, more importantly, what he wants—while, until very recently, Trump has shown no awareness that this knowledge is fundamental to diplomacy, to leadership, to making a smart deal.

Maybe Moon will snap Trump out of his torpor when they meet in Washington on Tuesday. Both of them want the summit with Kim to take place and, by some measure, succeed—Moon to reduce tensions and promote peace between North and South Korea, Trump to bolster his self-crafted reputation as a deal-maker extraordinaire. Moon has some idea of how to get to a plausible, if modest, accord; Trump has no idea. The question is whether Trump will acknowledge the disparity and let Moon write the script for the reality show in Singapore. If he doesn’t, he might as well bang on the table and shout, “Fuck you!”