South Korean President Moon Jae-in has made a good start to the New Year. Not only did he broker an agreement to bring North Korea to the Winter Olympic Games in Pyeongchang; he also convinced US President Donald Trump that doing so was in fact Trump’s idea.

With his Olympic coup, Moon has both managed the North Korean threat to the Games and avoided any backlash from the United States. Still, the agreement that North and South Korea reached in the border village of Panmunjom last month is unlikely to lead to renewed nuclear-disarmament talks.

Rather, once the Games are over, the North will likely use the current diplomatic opening to probe in other areas unrelated to its nuclear program, which, in turn, will raise a set of trying and familiar issues for the US–South Korea relationship.

After all, North Korean leader Kim Jong-un certainly wasn’t motivated by a genuine New Year’s resolution when he called for better relations with South Korea on 1 January. On the contrary, his gambit was in keeping with the North’s longstanding policy of trying to weaken the US–South Korean alliance.

In reaching out to the South, Kim wants to demonstrate that the North can live peacefully with its neighbours, even as it maintains a nuclear arsenal. More broadly, Kim is seeking to normalise the North’s status as a wannabe, self-identified nuclear power in the eyes of the world.

Achieving these goals, Kim hopes, will drive a wedge between the US and South Korea. He knows that Trump’s approval ratings in South Korea are far lower than his already-abysmal ratings in the US, so he is exploiting that fact to facilitate his nuclear-normalisation objective. And, of course, the North is always looking for opportunities to win relief from sanctions.

Moon, for his part, has handled Kim’s ‘peace offensive’ well. North Korea’s Olympians and cheerleaders will undoubtedly be greeted enthusiastically when they arrive by train in the South, and the crowd will roar its approval when athletes from the two countries march into the stadium under the same banner.

To be sure, the North Koreans will think they were invited to participate in the Games not in spite of their nuclear program, but because of it. From their perspective, South Korea seems to have developed a newfound respect—or fear—of what the North is becoming. And participation in the Olympics suggests that international isolation is a temporary fact of life, a toll on the road to fully recognised nuclear status. They might think that, soon enough, other countries will be lining up to offer the North a seat at the diplomatic table.

But Moon has made it clear that his government will not be seduced by the Olympic spirit. If North Korea’s leaders expect participation in the Games to lead to recognition of their country’s nuclear status, they will be waiting a long time. The South’s goal is to host a successful Olympic Games, after a year in which many countries questioned whether it was safe to send a delegation at all. Once the Games are over, the North will be facing a long winter of opprobrium and isolation.

That means the North would be wrong to assume that the South will beg it to reopen the Kaesong Industrial Complex, one of the most ambitious North–South cooperative efforts of the 2003–2009 détente era. Moon has shown no interest in such gestures. He understands that unilateral concessions will not improve South Korea’s position vis-à-vis the other regional and global powers reacting to North Korean behaviour.

Like the Saudis and others before him, Moon knows that the way to Trump’s heart is through his ego. But he also must manage the broader front of countries that are participating in historically strong sanctions against an abhorrent state. In that respect, Moon’s first big test will come immediately after the Olympics, when the South Korea – US Combined Forces Command will decide on its plans for future military exercises.

North Korea, of course, will object to such exercises, as it always does. But so, too, might China and Russia, which will accuse the US of reversing the Olympic thaw. Even so, a military alliance without exercises is like an orchestra without instruments. Moon most likely understands this, just as he realises that the importance of his country’s relationship with the US, despite its headaches and complexities, dwarfs that of any of its other partnerships around the world.

At the end of the day, a progressive South Korean government such as Moon’s always must demonstrate to the public that it can manage and safeguard the US relationship. So far, Moon has done that.