Xi has just been anointed President for life, and Kim was born a dictator-in-waiting.
When President Donald Trump meets with "Little Rocket Man
" in the coming weeks, the domestic power ratios will not be the same.
Trump is an elected leader at the head of a tumultuous administration in a divided nation. He is a catalyst for change -- but not necessarily master of the outcome.
Xi and Kim at least know they alone run the agenda at home. Even so, their meeting was no coming together of equals.
Even their toast hinted at the imbalance: Xi clasping a large glass of red wine and Kim a slender flute of white. It served the impression that Xi is the grown-up in the relationship, while Kim is an errant, spoiled child.
What propelled them together, however, was not the need for a drink, but Trump's threat to visit military havoc on Kim, shake his confidence and winkle him out of his reclusiveness for a face-to-face meeting.
Xi, who views Trump's diplomacy in Korea as meddling in his backyard, seems to have followed Trump's lead and got his own one-on-one ahead of the US President.
Had Trump not raised the "fire and fury" specter of a pre-emptive strike on Pyongyang, Kim might not have been tempted out of his "Hermit Kingdom."
In Beijing at Xi's side, Kim talked about "denuclearization" of the Korean Peninsula -- a first and a necessary tick in the box for Trump if he is to meet Kim.
But just because Trump precipitated this chain of events, it doesn't mean he controls where it is going. He lacks the latitude enjoyed by Xi and Kim at home and falls short of their diplomatic know-how -- especially in the region.
Xi has already shown his acumen by getting ahead of Trump and hosting Kim before the US leader's own North Korean tête-à-tête. And Kim has played a smart card not biting China's outstretched hand that helps keep his country afloat.
Kim knows he has to live with Xi -- likely for longer than he'll need to withstand Trump's invective and the uncertainty of where it leads.
But Trump may not be on as short a leash as Kim or Xi imagines. In recent weeks, he has been stripping out what he considers the weaklings in his administration and replacing them with hawks.
With John Bolton -- national security adviser -- and Mike Pompeo -- readying to take over at the State Department -- Trump gets enablers capable of amplifying his bellicosity, bolstering the credibility of military threats.
What every seasoned North Korea watcher is wondering now is how long Trump's style over substance -- moderately successful sanctions notwithstanding -- will work.
Kim's grandfather agreed to a denuclearization deal with President Bill Clinton in 1994, allowing for "the full normalization of political and economic relations with the United States."
Subsequently, both Kim's grandfather and father cheated on the deal. After vowing to stop processing plutonium, they covertly shifted to enriching uranium the other way to make a bomb.
Trump, of course, is more than aware of the duplicity he faces and has been known, by his own admission
, to use his own falsehoods.
The US leverage over Kim has so far been the threat of force, made more credible by Trump's volcanic unpredictability. Whether bigger doses of that is all Trump has in his arsenal when they meet is unclear.
Backed by his hawks, even if Trump is bluffing again, he will have effective wingmen to continue the illusion.
South Korean President Moon Jae-in appears to buy the possibility of a Trump-initiated conflagration. His successful Winter Olympics diplomacy -- inviting Kim's sister and a handful of North Korean athletes and cheerleaders to attend -- broke the ice, allowing the thaw we are witnessing today.
Kim's initial acceptance of Trump's willingness to meet face to face raised the question: What does he think the two men will talk about? Will there be more lies from both sides? Will Kim demand that North Korea be treated as a nuclear-capable nation?
Now Xi has inserted himself in the process; Trump's task -- without wanting to understate its complexity -- shifts from two- to three-dimensional chess.
He has gone from facing off against a leader who wants US forces removed from South Korea, to being confronted by a leader who not only wants US forces out of the Pacific region altogether but aspires to knocking America off its spot as world superpower.
With little more than bellicose bluster of military action in his pockets, Trump will get only one shot if Kim or Xi calls his bluff. That will be the moment his credibility is on the line -- and not just over North Korea.
Think President Barack Obama and his Syria "red line" comments in 2012
. It was game over: Russia stole the diplomatic lead and has held it since.
In this regard Trump's risks are even greater than Obama's. Not only is China a bigger global threat than Russia -- chomping at the bit for a pathway to global pre-eminence -- but Trump doesn't even have the full power of America's democracy behind him.
He has emasculated the State Department and shorn himself of solid diplomatic substance at his back. This has limited his options and leaves him at serious risk of Kim and Xi playing him off against each other.
An earlier version of this article gave an incorrect title for South Korean President Moon Jae-in.