Singapore (CNN) This week US President Donald Trump will finally come face to face with a leader who is virtually half his age, who inherited his position from his father and grandfather, and who is venerated by the millions of North Koreans who labor to keep his regime fed and in power.

The young dictator is due to meet with Trump on Tuesday morning in the first ever summit between a sitting US president and North Korean leader.

That the meeting is historic is indisputable. But that it is even taking place is even more remarkable, given that less than six months ago the two men were trading insults, flouting military capabilities and threatening each other with nuclear annihilation.

The subsequent climbdown has been as swift as it has been surprising.

But as the two adversaries prepare to meet in a specially prepared hotel conference room on a resort island in the city-state, their negotiating positions remain unchanged, and it is unclear whether this unprecedented encounter will yield anything substantive.

Extreme times

Almost exactly 12 months ago, on the second weekend of June 2017, North Korea's official newspaper, Rodong Sinmun, announced that the country was close to completing work on a long-range rocket that would be able to hit the US continent.

Weeks later, as Americans enjoyed the Fourth of July holiday weekend, North Korea successfully launched its first intercontinental ballistic missile (ICBM).

Over the course of the next five months, the Kim regime would go on to launch a further six missiles, each test nudging the country closer to war with the US.

JUST WATCHED Footage emerges of North Korea's ICBM launch Replay More Videos ... MUST WATCH Footage emerges of North Korea's ICBM launch 00:47

But if 2017 was a year of extreme belligerence from the North Korean leader, the first six months of 2018 have been the personification of the Pyongyang charm offensive.

The regime, having determined it could now consider itself a nuclear power, re-opened a hotline between North and South for the first time in 24 months in January this year, setting in motion a series of diplomatic firsts.

Spearheaded by South Korea, which remains the first, most likely, point of impact in any escalation on the Korean peninsula, the North's renewed embrace of the outside world began almost immediately.

In February, Kim dispatched his sister Kim Yo Jong to the Winter Olympics where she proceeded to captivate a world that had barely heard of her before.

that Trump would appreciate. This was followed in April by the inter-Korean summit between Kim Jong Un and South Korean President Moon Jae-in. A masterclass in showmanship, the meeting was replete with the kind of made-for-TV photo opportunitiesthat Trump would appreciate.

JUST WATCHED With one step, Kim Jong Un just made history Replay More Videos ... MUST WATCH With one step, Kim Jong Un just made history 02:35

In many ways it was a dress rehearsal for this week's event, particularly given the end result: a declaration to commit to denuclearization without an actionable time frame, and an end to the Korean War , which cannot happen without US involvement.

The two sides have more or less abided by an armistice signed by US Lt Gen William K Harrison on behalf of South Korea and his North Korean counterpart General Nam Il, on July 27, 1953.

It was a ceasefire to be put in place "until a final peaceful settlement is achieved."

Maximum pressure and maximum attention

Whether peace can be achieved on Tuesday will depend on the ability of the two leaders to strike a deal.

To date, Trump has veered wildly from the path of past presidents when it has come to North Korea.

For many observers it has been Trump's sheer volatility as commander-in-chief that has been the biggest reason the North Koreans sought this meeting.

Speaking to CNN, retired US diplomat William Courtney, described Trump's threatening language as "probably the right thing."

"My guess is North Korea's more open posture is a direct result of the pressure from the Trump administration and Trump personally," said Courtney, who is now an adjunct senior fellow at RAND Corporation.

"The North Koreans are probably concerned that the US is preparing scenarios of military force, that would be a reasonable presumption," said Courtney, referencing Trump's threat in August to unleash "fire and fury like the world has never seen," should North Korea continue to threaten the US.

The Trump administration's policy of "maximum pressure" is thought to have played a significant role, too, crippling the North Korean economy and forcing Kim to come to the table.

"Maximum pressure and maximum engagement at the same time," is how Vice President Mike Pence put it when he was on his way to the Pyeongchang Winter Olympics in South Korea in February.

JUST WATCHED Pence, Kim Jong Un's sister ignore each other Replay More Videos ... MUST WATCH Pence, Kim Jong Un's sister ignore each other 02:12

The administration has used unilateral and secondary penalties on Chinese and Russian firms that help North Korean banks launder money, allow North Korean workers to go abroad, and enable North Koreans to access international financial markets.

Going into this week, Kim Jong Un is likely to seek a reduction in these punishing sanctions.

And while Trump has come under criticism for agreeing to meet with Kim before any tangible denuclearization has occurred, he's been commended by others for flipping the format followed by past administrations.

"The script for North Korea's relations with the United States has varied with each passing presidential administration, but none has proved able to grapple with the nuclear issue," wrote Euan Graham of the Lowy Institute in a report on the current situation.

'They know we're watching'

A delegation of US officials was in South Korea for over a week, working on the substance of what might make it into discussions between Kim and Trump.

They have traveled regularly into the northern side of the demilitarized zone (DMZ) that separates the two Koreas to meet with Northern counterparts. Their communications are expected to continue long after the summit.

For its part, North Korea has made a great show of shelving its nuclear ambitions in advance of the summit.

In May it allowed foreign television crews to film explosions at a missile test site it said was no longer necessary for its weapons development.

No inspectors or proliferation experts were present . The White House said afterward that the North Koreans had promised they would be invited, but none were. Beyond the journalists who were allowed to see the openings to tunnels rigged with explosive wires, there was nothing to ascertain the extent of the demolition of the site or to attempt to glean intelligence that might shed some light on North Korea's nuclear capacity.

A prominent North Korea monitoring group reported last week that Pyongyang appears to have dismantled another site that was said to have been used to test medium-range ballistic missiles. And again, because there has been no independent inspection or verification, it's possible the event was for little more than publicity.

"They know we're watching," said Joseph S. Bermudez Jr., who authored the report by 38 North. "They deliberately practice what we call CCD -- camouflage, conceal and deception. We have to view this in that context," he told CNN.

Throughout this process, veterans of talks with North Korea, military and intelligence officials and retired diplomats have all voiced their skepticism that Pyongyang will ever give up its nuclear cache.

Among the doubters was Admiral Mike Mullen , the former Chairman of the Joint Chiefs of Staff.

"With Kim Jong Un, I wouldn't trust him," he told CNN. "I don't trust him. I would want to see his actions and not his words with respect to this. He would keep the nuclear weapons card in his hand and on his side for absolutely as long as possible."

JUST WATCHED Trump and Kim Jong Un's ups and downs Replay More Videos ... MUST WATCH Trump and Kim Jong Un's ups and downs 03:23

Having the nuclear weapons is what got Kim this far, says Mullen, "and for him to give that up would be very surprising to me and he'd have to give that up for something he values as much if not more and I'm not sure what that would be."

Beyond North Korea's ambitions for itself is the danger it poses beyond its own borders too.

Pyongyang has for decades proliferated weapons to rogue states including Iran and Syria, says Bruce Bechtol, a professor of political science at Angelo State University who has authored several books on North Korea.

Syria and North Korea evaded international sanctions by shipping missile parts which would be assembled in Syria by North Korean technicians, Bechtol argues in his latest book. He notes that a UN panel reported earlier this year that a North Korean technical delegation transferred valves and other parts during a visit to Syria in August 2016, and that between 2012 and 2017 some 39 shipments between the two countries carried arms including chemical weapons.

Iran, says Bechtol, is Pyongyang's best customer, the major purchaser of North Korea's conventional weapons, including submarines and ballistic missiles. Verification of dismantlement and economic pressure are critical in fighting North Korea's illicit trade, he says.

"Unless the United States is allowed to inspect all nuclear sites at the time of its choosing, and until it becomes clear that North Korea has completely dismantled its nuclear program, Washington must keep up the pressure on Pyongyang's illegal economic activities -- proliferation key among them," he wrote.

Allies on alert

There's perhaps no one who has personally staked as much on the success of getting Kim and Trump to meet than South Korea's Moon Jae-in . As someone who spoke of his intent to be remembered for bringing peace to the peninsula, Moon recognizes that the South is forever under the North's gaze.

Reunification is still a North Korean goal, however unlikely it might be today, and it wasn't long ago that speakers on both sides of the DMZ disseminated propaganda trying to derail the other side's agenda.

But for all of his determination to engage with the North, he has not jeopardized the South's security. He has supported Trump's threats of military retaliation and punitive sanctions.

JUST WATCHED Moon: The masterful dealmaker Replay More Videos ... MUST WATCH Moon: The masterful dealmaker 02:31

Moon reluctantly allowed the deployment of a US missile defense system to proceed last year, and the South Korean military regularly takes part in drills with the US military, to the consternation of not only Pyongyang but also Beijing, which sees the US presence as a hindrance to its own expansionist ambitions.

The South Koreans have been sanguine about the recent renewal of diplomatic overtures from the North, say experts.

"The South Koreans aren't fools either," said Andrew O'Neil, dean of the Griffith Business School at Griffith University in Australia. "They've been down this path many times before."

Another world leader watching closely is Japanese Prime Minister Shinzo Abe, who from the outset has viewed the Korean crisis with relentless skepticism

Even as Trump readied for his trip to Asia, Abe jetted to Washington to go over shared goals regarding the peninsula.

"Through summits and telephone conversations with President Trump, we have closely liaised and our positions are exactly the same," Abe told reporters last week. "Ahead of this historic US-North Korea summit I will meet President Trump to coordinate in order to advance progress on the nuclear issue, missiles and -- most importantly -- the abductees issue. I want to ensure the US-North Korea summit will be a success."

Abe's concerns reflect Japan's vulnerability regarding North Korea's conventional weapons arsenal, and a fear that Trump may settle on a compromise with Kim to pull back on ICBMs while rain checking any commitments on short and medium range missiles -- the very kind that landed in the Sea of Japan during tests last year.

And even as Trump reaps the domestic political benefits of having American detainees back on home soil after North Korea agreed to free them, there are countless other foreign nationals including Japanese and South Koreans that remain in custody in North Korea.

Who wins? Who loses?

In the short term, the optics of this meeting should give both leaders a political boost on their own domestic home fronts. For Kim, it is the fulfilment of a long-cherished ambition : to be seen as an equal, to be met and welcomed by a sitting American president -- the most powerful leader in the world -- and the recognition (through Pyongyang's lens) that North Korea is a nuclear power that commands respect on the world stage.

The footage of Kim meeting Trump will only serve to consolidate Kim's standing at home.

For Trump, the long-term impact depends on how well the talks go, what the two sides agree on, and whether the agreements fall apart down the road as they have done with past US administrations.

JUST WATCHED Trump: NK summit is "more than a photo op" Replay More Videos ... MUST WATCH Trump: NK summit is "more than a photo op" 07:41

Critics say that by granting the meeting, Trump has already made a concession, whereas Kim has made no real compromises on his opening bargaining stance. They say that the meeting is a prize that should be withheld until North Korea has irreversibly dismantled its nuclear program and has allowed inspectors into its country to verify this. They say that by giving the meeting away now, Trump loses leverage.

But others argue that such a tactic has failed with past administrations, and that by establishing a personal relationship with Kim up front, Trump has as good a chance as any other US president of gaining ground with the Kim regime.

Beyond that, questions remain. Is Kim truly ready to divest of his nukes? Is there a way the world could ever really verify anything he says or agrees to? Will Trump offer sanctions relief first and thereby cede more ground to North Korea and possibly duplicate past mistakes?

There may be a great deal of specificity that comes out of the Singapore summit, or there may be vague assurances of work to be done down the line. And Trump may find, like other American presidents before him, that the crisis on the Korean peninsula is as unsolvable as ever.