After a long train journey, Kim Jong-un will pull into Vietnam this week for his second summit with Donald Trump.

While many column inches have been written on the motivations of Donald Trump, what about those of Kim Jong-un?

Trying to figure out Mr Kim is not an exercise of intellectual fantasy. Any good negotiator will say that one of the keys to a successful negotiation is to spend as much or more time thinking about your opposite side’s position than your own. Has Mr Trump done this?

Figuring out Mr Kim is tough. I have seen the highly secretive state first hand, and wrote about my journey there in these pages and was able to gain rare footage from inside the hermit Kingdom here and here.

While that journey and film gives some insight into North Korea, one needs to look deeper to speculate on Mr Kim’s motivations.

As the first leader to have been born well after the Korean War ended, and hence, Mr Kim is free from the direct impact of war. Being the grandson of the hermit kingdom’s first ruler, and son of its second, he is also free of the effects of starvation and deprivation that have plagued his country.

For much of his childhood Mr Kim was far from Korea’s horrors, safely tucked away in international schools in Switzerland. Class friends have been reported as saying he was a shy student, fascinated by basketball and very much interested in politics and international affairs.

That time in Switzerland must have had an impact on him. For a start he must know that almost everything inside North Korea is a fraud.

Having lived outside of the country and seen the freedom the Swiss have, and the quality of life of ‘normal’ Swiss people, he must know that North Korea is built on a lie.

His school days would have been free of the party censorship and doctrine that children would have received in his homeland.

Being there in the 1990s, he would have experienced the end of communism, the fall of the Berlin wall and the overthrow of dictators such as Nicolae Ceaușescu in Romania.

Late Romanian president Nicolae Ceausescu and wife Elena after the Romanian Communist Party’s 14th congress in Bucharest in November 1989. Photo: Getty

Learning of the dictator’s death after the liberation of Romania and the gruesome method of his death, must have given Mr Kim a salutary warning. No dictator wants to end his life filled with bullets, crumpled at the base of a dirty wall with his corpse’s image flashed around the world.

The other thing that Mr Kim must have known was how brutal his family was. He must have known that a battle would ensure for succession. After all, it is rumoured that Mr Kim killed his uncle for disloyalty. Further, it is assumed by many that his half-brother, Kim Jong-nam, was assassinated on his orders to prevent any competition.

So, knowing all of this, when Mr Kim succeeded his father as leader, what were then and what are now, his options – assuming he wants to live to a ripe old age? I don’t for a second believe Mr Kim cares about his own people, but I do assume he wants to see his 80th birthday.

Could he have opened up North Korea rapidly? What would have happened then?

With the average North Korean now many centimetres shorter than their southern neighbours, with Seoul clearly better than Pyongyang, North Koreans would very quickly have realised that they had been sold a pup. The revolution that would have followed would almost certainly have led to Mr Kim’s brutal death.

Not a good option for him. For Mr Kim, the longevity of his regime is very personal indeed.

Could he have said ‘No thanks, I want to stay in Switzerland?’ Nope. He would have ended up with a handkerchief full of poison, like his half-brother.

Could he hope to rule as a brutal dictator all his life? Given that Mr Kim took over in his 20s, and given he’d like to live into his 80s, surely he would realise 60 years is a long time to keep command. Fidel Castro lasted 52 years in power, Kim Il-sung lasted 48. Few dictators in history have survived 60 years.

Could he rely on China?

Mr Kim’s father and grandfather did a good job in playing China and the US off against each other – a topic I have written on before. But who knows how that is going to play out?

Who knows if China would like to ‘tidy up’ North Korea some time into the future? After all, the Chinese walked across borders to take over territory in the name of ‘human rights’ before. That is one of the reasons China gave for going into Tibet.

So when thinking of a negotiation with Mr Kim, and assuming he wants to live to a ripe old age, nuclear weapons in his hands aren’t just an insurance policy against the US, they are an insurance policy against China, too.

This is not a negotiation, as some in the US would have you think, about putting pressure on Mr Kim through sanctions, perhaps bargain in a peace treaty, and then a de-nuclearisation could follow. As unpalatable as it sounds, any negotiation with Mr Kim must give him the one thing he really wants: 60 more years alive and comfortable.

Now how do we do that while still respecting human rights, still hoping for justice and still giving future generations of North Koreans what they deserve: Freedom, and their own life expectancy? That is the challenge Mr Trump faces.

Is he up to it?