The two leaders shook hands dramatically over the border. They say that Japan is "out of step from positive regional changes" and "has become isolated".
But many thorny problems lie ahead.
In retaliation, the North had sent over balloons carrying anti-South leaflets, along with starting their own broadcasts. They have always fallen apart.
Barack Obama won the 2009 Nobel Peace Prize just months into his presidency - an award many thought was premature and undeserved. Strategic trust is very low. This is what has happened on the Korean peninsula. "Everybody wants us - it has the chance to be a big event".
According to a summit accord, Kim and Moon agreed to achieve "a nuclear-free Korean Peninsula through complete denuclearisation", rather than clearly stating "a nuclear-free North Korea". This appears lofty but is ultimately vague, open to misinterpretations, and has no set time frame.
Three factors make Kim a liar in the eyes of his opponents. Any North Korean commitment without verification is simply not credible.
Here is the point where Friday's 'Panmunjom Declaration' falls down.
"There's something that I like about it because you're there, you're actually there".
But it will be Moon left holding the bag if this latest Kim gamble goes awry - not Trump's White House.
Such talk reflects rising hopes for coming discussions between Mr. Trump and Mr. Kim, the first summit meeting between the leaders of the United States and North Korea, which could happen by early June. Previous rounds of negotiation with North Korea took years and still failed. Speaking in 2014, former President Park Geun-hye also tried to promote a positive image of reunification, calling it a "jackpot" (daebak). Then, once Pyongyang secures lots of spoils and buys time, it's back to Kim family business as usual. So far Trump has not hinted what the US might give in return.
Lee traveled to Pyongyang in 2011 for Kim Jong Il's funeral and met Kim Jong Un - briefly - at that time. Trump's threatened walk-out would almost certainly send US relations with North Korea into a deep freeze.
Inviting international experts to oversee the closure of the Punggye-ri test site in May, Mr. Kim also slammed speculation that the site was already unusable after an underground tunnel there reportedly collapsed.
In the past, when Pyongyang needed to bargain for more time to keep working on its nuclear program, it didn't have to give up quite as much. This is not surprising, because the issues are so huge. I will respectfully leave. But at the summit level, a failed meeting could have dire consequences.
And the senator is not the only person to suggest the president should receive a Nobel Peace Prize for his part in bringing about the meeting, with a crowd at a rally in Michigan chanted "Nobel, Nobel" as Trump discussed the talks, Mediaite reported. And indeed, the emerging pundit consensus seems to be that the summit was long on principle and symbol, but short on detail.
Joseph Bermudez, an analyst at the US-based think tank 38 North, added, "They don't have an aircraft that can fly across the Pacific - most are quite old". Trump wrote on Twitter.
The idea that Trump is solely responsible for this breakthrough is, of course, preposterous. By tying Trump to summit diplomacy, a US attack is forestalled. The administration's objective is "complete, verifiable, irreversible denuclearization", Pompeo said. 2018's Korean détente now hangs on the outcome of the next summit.