In a quiet snub with big implications, North Korea’s young leader Kim Jong-un was refused an appointment in China this year.

The incident might have flown under the radar but for a Reuters report on Wednesday, wherein an anonymous source with close ties to both Pyongyang and Beijing confirmed that Kim Jong-un had requested a visit. It would have been his first official trip to China.

“There were too many things going on. [China] could not host Kim Jong-un,” said the source.

It could be that China is simply busy. This fall, it will undergo a major leadership change, with members of the elite Politburo Standing Committee handing power to newcomers. The process has been plagued by internal drama -- mysterious sackings, a salacious murder trial, car crashes and health problems -- as well as a countrywide economic slowdown.

Still, it’s odd that Beijing could not accommodate the leader of one of China’s closest allies, especially since Kim Jong-un’s father, the despotic and eccentric Kim Jong-il, made six visits to the mainland in the eight years before he died in December.

It is more likely that China’s refusal to host the Dear Leader is a calculated move, fitting a recent pattern of small-scale rifts between Beijing and Pyongyang. The shift could indicate a subtle change in policy for Beijing as China struggles to adapt to changing realities in the region.

Too Many Tiffs

China has plenty to be miffed about. Most memorably, Kim Jong-un ran afoul of Beijing when he decided to go ahead with a missile test in April. Pyongyang claimed it was a satellite launch, but international observers suspected it was a missile test. The rocket malfunctioned shortly after take-off, and the United Nations Security Council, including China, condemned the embarrassing experiment.

Furthermore, North Korea has been improving its relationship with Japan, China’s regional rival. In a sign that Kim Jong-un’s leadership may herald a new diplomatic direction for North Korea, officials from Pyongyang and Tokyo met in Beijing this August for their first direct talks in four years. Such a bond with Tokyo could potentially lessen North Korea’s decades-old dependence on China.

And then there are economic disputes. North Korea has a reputation as a shady business partner, but China tends not to publicize its neighbor’s weaknesses. That changed last month, when a Chinese corporation called Liaoning Xiyang Group allegedly lost more than $50 million in its dealings with a North Korean company Ryongbong Corporation. Xiyang’s complaints were covered in Chinese state media -- a rare disclosure -- while North Korean media rushed to downplay talk of a rift.

Most importantly, China is keen to prevent North Korea from stirring unnecessary controversy with its nuclear testing program. Pyongyang announced the completion of two successful nuclear weapons tests in 2006 and 2009, and the international community is determined to prevent another. China warned its neighbor not to conduct a third test amid rumors earlier this year that it was preparing to do so.

All of these rifts could explain China’s apparent iciness toward Kim Jong-un, but the fact remains that the historical bond between Beijing and Pyongyang is not so easily broken.

A Dependent Relationship

There is no question that North Korea needs China. The small communist nation relies on its giant neighbor, the second-largest economy on Earth, as its principal source of much-needed assistance.

Diplomatic isolation, economic sanctions, widespread poverty and ongoing food crises plague this country of more than 24 million people. The U.S. has been a prominent food aid donor to North Korea in the past, but that ended in early 2009 following a round of nuclear weapons testing provocation from Kim Jong-il.

China has stepped in to fill that gap, and not just in terms of aid. According to a report this year from the Council on Foreign Relations, Pyongyang-Beijing trade jumped to $5.63 billion in 2011, from $3.46 billion in 2010 -- a 62.5 percent increase. Meanwhile, trade with other significant partners, including South Korea, has been on the decline.

And Beijing has long turned a blind eye to North Korea’s deplorable human rights record. The people of North Korea live with an unrepresentative political system, strict censorship of the media and a skewed justice system that currently has up to 200,000 citizens detained in brutal gulags, where the prisoners perform forced labor for committing ill-defined "crimes against the state."

Without China, North Korea would have nowhere to turn for the support it so desperately needs.

Cuts Both Ways

China needs North Korea, too.

The People’s Republic has long-term plans for hegemony in the region, and the Korean Peninsula is integral to its efforts. By bolstering Pyongyang, Beijing hopes to play a leading role in the developing relationship between North Korea and South Korea. The two countries have been technically at war ever since a 1950-1953 battle between them ended in an armistice rather than a treaty.

A full reunion is still far off considering the high costs of such an endeavor, not to mention the two countries’ tense relationship. But South Korean President Lee Myung-Bak said just this month that reunification is “inevitable.” For China, any long-term geopolitical calculations must allow for that possibility.

South Korea is allied to the United States and Japan, both of whom rival China’s hegemony in the region. It is in Beijing’s interest, then, to keep its foot in the door in North Korea -- otherwise, it risks a loss of influence in the entire peninsula should a reunification come to pass.

For now, stability is Beijing’s goal for its communist neighbor. But the more Pyongyang irks the West through nuclear belligerence and inadequate development, the harder it will be for China to quell a diplomatic conflict that could upset the balance of power.

A Welcome Realignment

In that context, Chinese snubs -- refusing a visit from Kim Jong-un and publicizing the Xiyang spat -- are calculated admonishments rather than serious dismissals.

It is in Beijing’s best interests for Pyongyang to avoid stirring the pot over its nuclear ambitions, which would incur the ire of the West at an inopportune time. Not only is Beijing is in the middle of a fraught leadership change; it is also dealing with the U.S. administration’s recent “pivot” to the East in an effort to gain more influence in Asia, as well as a looming confrontation with Japan over island territories in the East China Sea.

So if Kim Jong-un wants a slot on the Politburo’s busy agenda, he may have to adhere to certain guidelines.

“Kim Jong-un wanted to come, but it was not a convenient time," said another anonymous source with insights into China's foreign policy to Reuters.

"From China's perspective, he has to come with something positive," added the source, suggesting that the Dear Leader must agree to dial back North Korea’s nuclear plans.

In other words, Beijing may now be using its overwhelming power over Pyongyang to effect a policy shift in North Korea -- more stability, less provocation. And even if China is acting out of pure self-interest, such a shift would be a welcome development for the West as well as the East.