FILE - In this April 27, 2018, file photo, North Korean security persons run by a car carrying North Korean leader Kim Jong Un return to the North side for a lunch break after a morning meeting with South Korean President Moon Jae-in at the border village of Panmunjom in Demilitarized Zone. Kim is on a rare trip abroad as he leaves the all-encompassing bubble of his locked-down stronghold of Pyongyang and steps off a jet onto Singaporean soil for his planned sit-down witU.S. President Donald Trump on Tuesday, June 12, 2018. (Korea Summit Press Pool via AP, File)

SINGAPORE (AP) — Spare a moment, as you anticipate one of the most unusual summits in modern history, to consider North Korea's leader as he left the all-encompassing bubble of his locked-down stronghold of Pyongyang on Sunday and stepped off a jet onto Singapore soil for his planned sit-down with President Donald Trump on Tuesday.

There's just no recent precedent for the gamble Kim Jong Un is taking.

As far as we know, his despot father only traveled out of the country by train, and rarely at that, because of fears of assassination. Kim, up until his recent high-profile summit with South Korea's president on the southern side of their shared border, has usually hunkered down behind his vast propaganda and security services, or made short trips to autocrat-friendly China. 

While Singapore has authoritarian leanings, it is still a thriving bastion of capitalism and wealth, and Kim will be performing his high-stakes diplomatic tight-rope walk in front of 3,000 international journalists, including a huge contingent from the ultra-aggressive South Korean press — sometimes referred to by Pyongyang as "reptile media" — two of whom were arrested by Singapore police investigating a report of trespassing at the residence of the North Korean ambassador.

While he famously attended school in Switzerland, traveling this far as supreme leader is an entirely different matter for someone used to being the most revered, most protected, most deferred to human in his country of 25 million. Kim is, essentially, upsetting two decades of carefully choreographed North Korean statecraft and stepping into the unknown.

There's wild speculation about how Kim will perform on the world stage, although one question was answered Sunday: His grim-faced, well-muscled bodyguards marched alongside his armored limousine at one point in Singapore, just as they did when he met the South Korean leader in April. But amid the curiosity is an even more fundamental question: Why is he taking this risk at all?

Here's a look:

THE LOGISTICS

First the nuts and bolts: How do you protect what many North Koreans consider their single most precious resource, the third member of the Kim family to rule and a direct descendant of North Korea's worshipped founder Kim Il Sung?

Hundreds of North Korean security experts have no doubt been up nights wondering how to safeguard Kim Jong Un since Trump shocked the world by accepting the North's invitation to meet.

Kim arrived Sunday on a Chinese plane, not his official plane, which is called "Chammae-1" and named after the goshawk, North Korea's national bird.

Kim may have shipped over the massive bulletproof and fireproof limousine that became a social media sensation when Kim was shown being driven across the border between the Koreas during his first summit with South Korean President Moon Jae-in, in April, with a dozen staunch bodyguards encircling the auto. He could be seen speeding through Singapore on Sunday in a black limousine adorned with large North Korean flags.

Singapore's The Straits Times reported earlier this month that the Singapore government declared that four black BMW sedans with armored bodies that can withstand gunshots, explosives and grenades were exempt from certain traffic rules through June 30. The newspaper said the vehicles weren't from a local authorized dealer, which suggests the cars were brought in specifically for the summit and may be used by Kim.

Kim's bodyguards traveled with him, providing trusted protection to back up local Singapore security who were controlling the perimeter and crowds,

One benefit of Singapore from the North Korean point of view is that there will probably not be any anti-North Korea protests during Kim's stay. "Singapore is like a police state. How can such rallies take place there? Anyone involved in rallies would be arrested," said Choi Kang, vice president of Seoul's Asan Institute for Policy Studies.

Kim arrived Sunday at the St. Regis hotel, where his close aide has been based as he leads a North Korean advance team arranging security and logistics details. South Korea's Hankook Ilbo reported that Singapore recommended the St. Regis, which hosted Chinese President Xi Jinping during his 2015 summit with Taiwanese President Ma Ying-jeou, because it can be easily secured.

WHY'S HE TAKING THE RISK?