Who would have guessed that a Trump crowd 15 months into his presidency would be chanting, “Nobel! Nobel! Nobel!”

As in Alfred Nobel, the Swedish inventor and philanthropist who created the eponymous prizes, including one for peace. The prize was on the minds of Trump fans thanks to developments on the Korean peninsula, where Kim Jong Un has stopped testing missiles and started love-bombing the South.

Donald Trump has a typically modulated view of how much he had to do with this. “Everything,” he told his Michigan rally. If that’s too boastful, the president deserves credit for breaking with Barack Obama’s policy of “strategic patience” that effectively meant accepting North Korea’s march toward a nuclear-tipped ICBM.

Trump tightened up on a sanctions regime that had considerable slack (it still does). And he undertook a Trumpian pressure campaign consisting of insults, fiery rhetoric, extreme ambiguity about his true intentions and braggadocio about the size of his nuclear button. If many in the United States were freaked out, it stands to reason that Kim, at the receiving end of the bullying and potentially of something much worse, took notice.

This is all to the good, but the problem is that nothing we have seen so far from Kim is inconsistent with the decadeslong North Korean diplomatic pattern of selling us the same fake concessions in exchange for sanctions relief and economic benefits.

Inspiring talk with the South Koreans about a breakthrough to a new era of peace? To paraphrase Barack Obama’s famous put-down of Mitt Romney, 1992, 2000 and 2007 all want their foreign policies back. High-flying joint declarations in each of those years proved meaningless.

Mothballing nuclear facilities as a sign of good faith? Kim is inviting the press to witness the shuttering of a tunnel complex used to test nuclear weapons. His father destroyed a cooling tower in front of the international media in 2008.

Promises to the U.S. to disarm? Pyongyang said it was ending its illicit plutonium program in the 1994 Agreed Framework. It said it was giving up “all nuclear weapons and existing nuclear programs” in 2005 as part of the so-called Six-Party Talks. It said in 2007 that it was agreeing to specific steps to follow through on its 2005 commitment. All came to naught.

This is why the ultimate test of Trump’s mettle isn’t getting Kim to the negotiating table, but being willing to walk away from it.

The temptation will be very strong to go down the path we’ve trod so many times before. Negotiations develop a momentum of their own, especially ones this public and high-stakes. Any deal, even an inadequate one, would hold out the alluring possibility of changing the political dynamic in the run-up to the midterms. And hold out the possibility of Trump getting, if not a Nobel Peace Prize, the kind approval from elites that he simultaneously disdains and craves.

So far, Trump is saying the right things, both about turning aside an ill-considered deal and keeping up “maximum pressure” on the North.

He’d do well to familiarize himself with Ronald Reagan’s high-wire summit with Soviet leader Mikhail Gorbachev at Reykjavik in 1986. They audaciously discussed eliminating all nuclear weapons, before the Soviets demanded an end to the SDI missile-defense program. Reagan walked away. The summit was considered a failure, but Reagan had convinced the Soviets that we weren’t going to give up our technological advantage over them.

Trump should conceive of his meeting with Kim as a continuation of his campaign of coercive diplomacy. Should it (in all likelihood) fail to elicit a credible decision by the North to give up its nukes, it should be the pivot toward an even harsher clampdown on the North.

None of the great and good are going to shower Trump with accolades for being cleareyed and tough-minded, but that’s what his negotiations with Kim require. The Nobel can wait.

Rich Lowry can be reached via e-mail: comments.lowry@nationalreview.com.