If you are not making adequate progress in a negotiation, it may be rational to walk away from the bargaining table. But that is only the case if your adversary is more anxious to reach an agreement than you are.

North Korea is by no means immune from external pressure; the claim that sanctions have no effect is contradicted by Kim Jong Un’s preoccupation with the economy in recent months.

Nonetheless, Trump’s cancellation-by-tweet appears to reflect his erratic policymaking style, a misguided effort to link North Korea to economic negotiations with the Chinese trade talks and above all sheer pique and an effort to divert attention from mounting political problems at home.

The only positive spin that can be put on recent developments is that Trump could well reverse himself yet again, particularly if Moon Jae-in can set the stage for a Kim Jong Un visit to the UN in the fall or a second summit.

Let’s start with the timing and content of the tweets themselves. In the disorienting world of Trump-time, it is easy to forget that it was only last Thursday that Secretary Pompeo announced his fourth trip to Pyongyang and the appointment of a special representative.

These moves were generally well-received. Pompeo’s third trip had gotten nowhere. The new appointment, Stephen Biegun, had no meaningful Korea experience.

But it was better to have a competent professional on the case than requiring Pompeo to manage all aspects of the negotiations or rely on part-time support from Sung Kim, who is doubling as Ambassador to Manila.

The cancellation tweet revealed, yet again, some of the distinctive disabilities of the president’s decision-making style.

The first is the unwillingness to grant latitude to his own team, and the propensity to disrupt not only abroad but at home.

Second is the president’s growing preoccupation with his risky China trade gambit and a confusing effort at linkage. The president’s tweet stated that “because of our much tougher Trading stance with China, I do not believe they are helping with the process of denuclearization as they once were”). It is hard to fathom, however, why canceling Pompeo’s trip puts additional pressure on Xi Jinping, who is taking the unprecedented step of going to Pyongyang in early September.

It is hard to fathom … why canceling Pompeo’s trip puts additional pressure on Xi Jinping, who is taking the unprecedented step of going to Pyongyang in early September

Finally, it is hard to communicate the looming domestic turmoil in the United States, which edges ever closer to constitutional crisis.

On the heels of successful indictments of Trump’s attorney Michael Cohen and former campaign manager Paul Manafort, the language emanating from the President is escalating. Most dangerously, this is visible in the drumbeat of attacks on the Department of Justice and the Mueller investigation and in the willingness to effectively collapse judicial checks by publicly supporting criminal defendants at trial and even hinting at pardons.

The president is clearly reaching for foreign and domestic policy moves that are hastily-conceived distractions.

If there is one thin substantive reed on which the president’s cancellation might rest, it would be on perceived North Korean weakness and on pressure that Moon Jae-in may bring to bear on Pyongyang.

Maintaining the sanctions regime is proving difficult, but the multiple reports of leakage should not be misinterpreted as signaling business as usual. First half trade with China is still off by over 50% from 2017. The loss of North Korean exports (down 88%) will clearly not be fully made up by smuggling or by unrequited Chinese exports, which fell far less (39%), still well behind last year.

That Kim Jong Un is touring economic as opposed to military facilities may be a subtle—or misleading—signal of pacific intent. But it is equally plausible that economic pressure from sanctions continues to mount.

If that is the case, and bilateral negotiations with the U.S. are now stalled, much will fall on the shoulders of the Moon Jae-in administration.

Maintaining the sanctions regime is proving difficult, but the multiple reports of leakage should not be misinterpreted as signaling business as usual

President Moon has been forced into a delicate balancing act, seeking simultaneously to keep momentum in North-South relations while not openly alienating the U.S.

Family reunions, the opening of a liaison office, discussions of reconnecting railroads and yet another summit are all examples of Moon’s larger strategy: to make tantalizing promises of what is possible with the North while no doubt pressing the North in private for concessions on the nuclear front that will move the United States.

Those of us who supported the summit recognized that it was a calculated risk and acknowledged that there was inadequate time to develop a roadmap for future negotiations.

The perennial question in such negotiations is how incremental concessions will be exchanged.

North Korea has put a number of symbolic, limited and largely reversible things on the table: the razing of engine test stand prior to the summit; blowing up entrances to tunnels at Punggye-ri, some dismantlement at the Sohae test site. Yet in the absence of a declaration and more definitive pause, contradictory evidence of intent persists, for example in persistent if debated reports of ongoing nuclear and missile developments.

At this juncture, there are two things that South Korea might do. The first is to get some tangible concession, however modest, from North Korea that it can carry to the United States. My favored starting point: opening a process that would generate a meaningful North Korean declaration of its capabilities.

The second, however, is to “go big” and seek to break the deadlock with a second Trump-Kim summit.

Given the outcome of the first summit, this may seem like a misguided step.

Yet the purpose of summits is precisely to break logjams where lower level negotiating processes have failed. If Kim Jong Un were to come to New York for the UN General Assembly meetings in the fall, he would almost certainly have to bring something to the table. The U.S. would have to start thinking about concessions too, such as how to word a statement on ending the Korean War.

As with Singapore, would the parties really be worse off by taking more calculated risks? The alternative is where we are, which is getting nowhere fast.

Main picture: Dan Scavino Jr, White House