The first inter-Korean summit of 2018, a sunny spectacle in late April, reduced war fears on the peninsula. The second, an emergency one in May, helped ensure a historic meeting between North Korean leader Kim Jong Un and President Trump came off.
Now, at a third summit with Kim next week in the North Korean capital, Pyongyang, South Korean President Moon Jae-in faces his toughest challenge yet: delivering something substantive that goes beyond previous vague statements on denuclearization and helps get U.S.-North Korea talks back on track.
Negotiations between Washington and Pyongyang have sputtered in recent weeks, raising doubts about whether Kim is truly willing to relinquish his nuclear arsenal and putting pressure on Moon to broker progress once again.
The result will probably be a crucial indicator of how the larger nuclear negotiations with the U.S. will proceed. Moon will try to get Kim to express more clearly that he's prepared to abandon his nuclear weapons, which could create momentum for a second Kim-Trump summit.
Whether Moon succeeds, fails or falls somewhere in between, the session could help answer a persistent question: When Kim says he supports the "complete denuclearization of the Korean peninsula," what does he actually mean?
Moon heads to Pyongyang on Tuesday facing lingering questions over his claim that Kim, during his conversations with South Korean officials, has privately expressed a genuine interest in dealing away his nuclear weapons and missiles.
The wave of optimism that surrounded the first two inter-Korean summits in April and May and the Singapore meeting between Trump and Kim in June conveniently overlooked disagreements about what exactly Kim had committed to.
"The third summit will bring more clarity to what North Korea means with the complete denuclearization of the peninsula," said Kim Tae-woo, former president of Seoul's government-funded Korea Institute for National Unification. "If the North has been negotiating with goodwill all this time, Moon will be able to return with good results. But, regrettably, I see that possibility as low."
At his meetings with Moon and Trump, Kim signed statements pledging the complete denuclearization of the peninsula. But the North for decades has been pushing a concept of denuclearization that bears no resemblance to the American definition, vowing to pursue nuclear development until the United States removes its troops from South Korea and the nuclear umbrella defending South Korea and Japan.
The differences prompted Trump to cancel Secretary of State Mike Pompeo's planned visit to North Korea last month. After an earlier Pompeo visit, Pyongyang accused Washington of making "unilateral and gangster-like" demands on denuclearization and bristled at the idea that it must take significant steps toward dismantling its nuclear program before a peace treaty is signed or international sanctions are lifted.
Moon, the son of North Korean war refugees, is eager to keep the nuclear diplomacy alive, not just to keep a lid on tensions, but also to advance his ambitious plans for engagement with the North, including joint economic projects and reconnecting inter-Korean roads and railways. These projects are held back by the sanctions against North Korea.