(CNN) If all the world had seen of Kim Jong Un until now was the smiling, tactile, affectionate young man who strolled nonchalantly through the wooded glades of the demilitarized zone on Friday, it could be forgiven for thinking a brutal tyrant had been deeply misunderstood.

Friday's historic encounter between North and South Korea gave a world leader who has hitherto shunned the foreign media more camera time than ever before. Every mannerism, every lift of an eyebrow was studied and speculated upon.

For most of the day, Kim and South Korean President Moon Jae-in were followed around by television cameras and photographers as they picked their way through a series of intricately choreographed scenes in Panmunjom, the "peace village" in the DMZ that was the venue for their talks.

There was the moment when Kim stepped into the South, across the demarcation line that separates the two Koreas (and Moon briefly stepped over into the North). Then they held almost two hours of talks in the morning, planted a symbolic tree, and strolled alone in a wooded area of the DMZ where they spoke without officials for 30 minutes.

They embraced, held hands, and traded pleasantries. Kim even thanked the media for coming.

North Korean leader Kim Jong Un (L) and South Korean President Moon Jae-in hold hands as they cross the Military Demarcation Line at the DMZ on April 27.

Finally, in the late afternoon, the substance: The Panmunjom Declaration for Peace, Prosperity and Unification on the Korean Peninsula, which commits the two countries to denuclearization and talks to bring a formal end to conflict between the two nations.

So can it really be possible that, after decades of mutual distrust that recently appeared to bring the two nations to the brink of war, a complete reversal is on the cards and that peace is a realistic prospect?

The big players who loom large over the Korean conflict appear deeply skeptical. Notwithstanding President Donald Trump's enthusiastic tweets ("Good things are happening, but only time will tell!") the White House statement was decidedly cool.

"On the occasion of Republic of Korea President Moon Jae-in's historic meeting with North Korean leader Kim Jong Un, we wish the Korean people well," it said. "We are hopeful that talks will achieve progress toward a future of peace and prosperity for the entire Korean Peninsula."

Japan's Prime Minister Shinzo Abe could barely conceal his doubts. "I strongly ... hope that North Korea will take concrete actions. I will keep close eyes on North Korea's actions from now," he said. In other words, I'll believe denuclearization when I see it.

Some longtime North Korea watchers harbor significant doubts that there could have been any real transformation of the man who just under a year ago spoke of intercontinental ballistic missiles that could reach the US mainland as a "gift package to the Yankees."

"How many pictures of him are there where he's at a nuclear facility at a missile test and he's smiling and happy?" asked Catherine Dill, a Senior Research Associate at the James Martin Center for Nonproliferation Studies at the Middlebury Institute of International Studies at Monterey.

"Just because he seems like a jolly man doesn't mean that his intentions are pure, or that he's unable to launch a missile again," she told CNN. "A lot of the summit, even if the true intention of President Moon Jae-in and Kim Jong Un was to work towards peace at some point, there's a lot of pageantry involved. So in some sense, he was acting."

North Korean leader Kim Jong Un (L) and South Korean President Moon Jae-in at the Inter-Korean Summit on Friday in Panmunjom.

Security and nonproliferation experts nevertheless welcomed Friday's historic meeting as a significant achievement for Moon and his policy of engagement with North Korea. But while some progress may occur, some see the chances of denuclearization, at least in the sense that the West would understand it, as slim.

"The prospects of North Korea dismantling its nuclear and ballistic missile arsenals remain as dim as ever," said Miha Hribenik, a senior Asia analyst at global risk consultancy Verisk Maplecroft.

More at https://edition.cnn.com/2018/04/27/asia/kim-jong-un-north-south-korea-summit-intl/index.html