The past week brought a dramatic list of concessions from North Korea, a pariah state that spent much of last year prompting international anxiety with its repeated missile launches and nuclear weapons advancement.
The North in recent days said it was prepared to suspend those provocative missile launches, close its major nuclear-testing site and acknowledge that United States troops would likely remain in neighboring South Korea, a nation with whom it's still technically at war.
While far from a firm solution to the crisis, these rapid concessions have raised hopes and prompted questions in advance of next week's historic summit between the South's democratically elected President Moon Jae-in, and the North's dynastic leader Kim Jong Un. A meeting soon between Kim and President Trump is also planned.
"These are some pretty big gives that they've thrown out there in the last week or so, and it's remarkable that they are doing that," said Robert Kelly, a political science professor at Pusan University in South Korea who blogs about Asia security issues. "So I think the growing question is, 'What has changed?'"
The motivations for the latest moves by the North, which come after a diplomatic opening created by the Winter Olympics, have divided political leaders and analysts here, said Paik Hak-soon, who directs the Center for North Korean Studies at the Sejong Institute, a South Korean think tank.
Progressives in South Korea remain hopeful or even confident that the North is ready to change to modernize its economy, while conservatives are more cautious and predisposed to skepticism about its motives.
"I don't know which one is right," Paik said, "but obviously there are two competing theories."
Whatever the North's motivation, which seems economic, the tension felt here has been lowered dramatically since last year, when the North tested a powerful hydrogen bomb in September and then launched an intercontinental ballistic missile more than 2,500 miles into space. That device could theoretically have reached Washington, D.C.
Both incidents, which further isolated the totalitarian state, capped a year of repeated missile and engine tests that violated United Nations resolutions. They also probably prompted its closest trading partner, China, to get more serious about pressuring the North by enforcing sanctions.
The political divide in the South has been around for decades. But the North's behavior in 2017 also seems to have hardened Moon's resolve for denuclearization as a marker for its seriousness about negotiations. The president, who took office pledging more dialogue with the North, has also repeatedly praised President Trump for helping create an environment in which Kim would be willing to change course.
Paik said progressives, such as Moon supporters and aides, believe that Kim, 34, is a different leader than his late father, Kim Jong Il, and his late grandfather, Kim Il Sung, the nation's communist patriarch.
Perhaps the younger Kim, confident in his position to negotiate because of his nation's nuclear development, hopes to strike a deal to dramatically improve the North's economy, which has struggled to modernize.
Its per capita economic output remains among the lowest in the world, about the same as Haiti and Gambia, according to the CIA.
The nuclear issue is one of three central topics for Moon's upcoming meeting with Kim, scheduled for Friday at Panmunjom, the diplomatic outpost inside the Demilitarized Zone that separates the two nations.
Even the venue — a "peace" house on the South Korean side of the complex — seems a concession. Two previous summits between Korean leaders, in 2000 and 2007, were held in Pyongyang, the North's capital.
Also on the agenda are improved inter-Koreanj relations and a potential peace agreement, perhaps leading to the formal end of the Korean War, a brutal conflict that formalized the post-World War II division of the peninsula, where most residents share a common language, ethnic identity and historical culture.
Resolving the nuclear issue is the key for easing tensions and ending the war, the South and United States have said. It remains unclear what "denuclearization" might mean to the North, which experts believe already has more than a dozen weapons and the ability to produce more even if the current arsenal were frozen or dismantled.
On the other side of the debate, conservatives in South Korea suspect that the North's words are just an attempt to use clever tactics. They believe that the economic pressure imposed by the international community is working, and perhaps that Kim is on the ropes.
They also say that Kim's recent overtures, however substantial they may appear to be, cost him little.
The nuclear test site, near the northeastern village of Punggye-ri, is believed to have been badly damaged — perhaps even destroyed — in last year's powerful test and several before it.
The North also already chose voluntarily to suspend its missile testing, in practice, for the last several months during the Games, held in Pyeongchang, South Korea, where the two nations marched as one during the opening ceremony and fielded a joint women's hockey team.
The leaders of Moon's political opposition said Saturday they want "complete, verifiable and irreversible denuclearization" from the North.
Some suggest that perhaps the North's motives reflect both its desire to change its economy and a confidence to do so by leveraging its emerging nuclear capabilities.
"What if it's both?" asked John Delury, an associate professor of political science at Yonsei University in Seoul, on Twitter. "A concession born of strength."
The answers to these questions could have obvious consequences for China, which recently hosted Kim in Beijing, and the United States, which has held regular calls between Trump and Moon and their staffs.
Both want to influence events and maintain power in the region. And any binding peace treaty ending the war would probably require the acceptance of those two nations, whose representatives were the actual signatories to the armistice that ended the fighting in 1953.
Meanwhile, the world waits for more details about the reclusive North's motives, actions — and possibly demands.
"Has there been a real change in North Korea? Is there some behind-the-scenes deal with the South that we don't know about? We don't know," Kelly said. "It's all happening very fast."