This is most evident on international agreements. Consider the North Korea negotiation, assuming that plans for the summit manage to get back on track after this week’s blowup. Managing to arrange a face-to-face meeting is a major coup, but it’s still a high-stakes situation. In the lead-up, some Korea experts fear the U.S. has already given up too much leverage, and Trump is reportedly taking a worryingly casual approach to preparing for the meeting. The summit itself brings new risks, especially if Trump is unprepared or disposed to walk away quickly, because once a top-level conference has been tried and fails, it leaves few options: either a return to the status quo—which has favored nuclear proliferation—or war. As Victor Cha, a Korea expert who Trump considered for ambassador to Seoul, put it in March, “Failed negotiations at the summit level leave all parties with no other recourse for diplomacy. In which case, as Mr. Trump has said, we really will have ‘run out of road’ on North Korea.”

Were Kim Jong Un and Trump sitting down to try to hammer out a real-estate deal, the ramifications of a failure would likely be few. Trump could simply seek new opportunities elsewhere. That doesn’t work in diplomacy, though. It’s not as if the U.S. can simply move on to another rogue state and try to negotiate with them, since the North Korea problem would remain unsolved. A different mutation of the same dynamic has transpired with Iran. Trump has pulled out of the nuclear agreement with Tehran, but he continues to speak hopefully about striking a new and better deal, overlooking the damaging effects of a breach of trust on the first deal. One reason Kerry was so eager to strike an accord was his fear that failure would mean Iranian proliferation.

Trump has displayed a similarly cavalier attitude in domestic politics, where he was surprisingly unbothered by the collapse of his attempt to repeal Obamacare. Here, echoing his approach to North Korea, Trump made a great deal of noise about major legislation but showed little interest in actually boning up on the details of health policy or congressional horse-trading needed to shepherd a bill through. Once the effort collapsed, the president shrugged and moved on. The failure broke a promise to the GOP base, and Democrats are finding health care to be a potent issue in this year’s midterm elections.

These failures are, if not final, certainly enduring. Pulling out of the Iran deal means no new deal is likely. Moving on from health care means Trump won’t attempt an overhaul again in the foreseeable future. And walking away from the table in Singapore would probably end any hope of a diplomatic resolution with North Korea. If the president has not grasped this, it’s because his many years in business taught him a different lesson.