A volatile negotiating style is sometimes a sign of an inexperienced or uncertain bargainer, notes the chief negotiator for one of America’s major unions. He explains in an interview that inconsistency and changing priorities are “inevitably taken as lack of commitment to the process and a sign of weakness” by negotiators and mediators. But it’s Trump’s approach, and however bizarre the route, he’s nearing a diplomatic breakthrough.

Through it all, Trump has kept returning to his baseline: He wants a deal, but he isn’t willing to alter his demand for denuclearization. North Korea made a series of concessions, including releasing hostages, without any reciprocal U.S. easing of sanctions. “We’re controlling the pace,” insists one key U.S. official. And, for now, this approach seems to be working.

What comes next? What are the fixed “red lines” for each side, and where’s the wiggle room? How will an initial framework agreement be translated into specific commitments, and how will these be monitored? How will North Korea be rewarded for its compliance — in removal of sanctions and in foreign investment? I couldn’t get clear answers from U.S. or South Korean officials, maybe because there aren’t any yet.