It has been a bad month for Chinese-North Korean relations.
The assassination of Kim Jong Nam, the older brother of North Korean leader Kim Jong Un who had been under Chinese protection and living in Macau, was followed by another round of missile launches by Pyongyang, stirring vocal anger from Seoul and Tokyo and quiet fury from Beijing.
At the same time, discussions between US Secretary of State Rex Tillerson and Chinese Foreign Ministry counterparts coincided with a Chinese cutoff of coal imports from North Korea, raising expectations that the US and China may be able to cooperate to further punish Kim.
Tillerson claimed during his confirmation hearings that China possesses "complete control over what sustains the Government of North Korea". Responding to an earlier missile test by North Korea, Senate Minority Leader Chuck Schumer said essentially the same thing.
North Korea is looking to offset not only military threats from the United States but also what it increasingly perceives as economic and ideological threats from China.China has considerable clout over North Korea but not enough to push Pyongyang away from what it considers priorities for national survival, such as nuclear weapons and the uprooting of any chutes of the slightest dissent that might lead to systemic political change.
How strong are Sino-North Korean relations right now? And what might this mean for China's willingness to enforce sanctions?
The triangular relationship between North Korea, China, and the United States has changed a great deal since the era of the Korean War. At the request of then-leader Kim Il Sung, Mao Zedong's Chinese troops saved the North and stuck around to secure the country until their exit was negotiated in 1958. Anti-Americanism was at the core of their shared interests.
That relationship has changed a great deal since the 1970s and 1980s, when China resumed wide-ranging interactions with the US, began doing business with South Korea, and blanched at the growing personality cult around the North Korean supreme leader.
China's heralded "reform and opening up" brought in foreign culture that alarmed North Korean leaders, who also bridled at Deng Xiaoping's slowness to accept the principles of hereditary succession that North Korea still clings to today.
Nevertheless, the North Koreans stood by Beijing after the 1989 Tiananmen Square massacre and have been reliable supporters at the United Nations in defence of China's controversial policies towards Tibet and Taiwan. For China, allies like this may be annoying, but they are hard to come by.
The notion that China in reality does not want North Korea to give up its nuclear weapons seems misplaced.
To be sure, no one in Beijing is losing sleep when Japan - a shared adversary - complains that it feels threatened by North Korea or demands its abducted citizens back.
The tensions suddenly unleashed in Asia come before President Trump's full national security team is in place https://t.co/zx3LNAEtS8
But China does not want to see North Korea sufficiently emboldened that the Kim family again begins itching for kinetic military action against South Korea or the US troops stationed on the peninsula.
China's support of multiple rounds of international sanctions punishing North Korea is not just theater but a genuine indication of Beijing's anger. The problems between Beijing and Pyongyang are real and manageable, not a staged set of contradictions underneath which the North Koreans act as China's puppets. Since Chinese troops left North Korea in 1958, Beijing has had limited leverage over the country's policy direction.
Tillerson and other critics are certainly right that Beijing can bring tremendous economic pressure to bear on North Korea. As North Korean economic cooperation and exchange with South Korea have nosedived, Chinese producers, extractive industries, and even small businesses have filled the gap.
But Beijing's latest initiatives may prompt more hostility than cooperation from North Korea. The implications of the massive "One Belt, One Road" scheme are dire for the North.
China has announced grand plans to transform its international frontiers, creating links with those areas via trade and transportation links, including high-speed rail. Along with this infrastructural emphasis come increased cross-border cultural ties on a Chinese basis, including more Confucius Institutes for language teaching, leveraging of overseas Chinese, and further outward migration of Chinese citizens and corporate interests.
This all goes fundamentally against North Korea's mode of economic interaction with China since the late 1950s, which stresses chajusong, or self-reliance, and hedges foreign relations against Chinese trade surplus balances wherever possible.
And the North is willing to take shocking moves against China for the sake of preserving that self-reliance. Recent examples include the violent expropriation of the North Korean operations of Haicheng, a huge Chinese steel conglomerate, in 2012 and the sudden execution of Kim Jong Un's uncle Jang Song Thaek, China's main interlocutor in the North, in December 2013.
China's rise to international power has been meteoric, and its neighbours in Pyongyang have naturally noticed. Watching the Chinese economy take off while North Korea's has tanked at worst, and plateaued at best, has been instructive and probably galling for North Korean leaders.
And it is not just North Korean leaders and officials who can see China's prosperity - the people of the border region do as well, and Chinese tourists are able to flaunt their wealth in most of North Korea's cities far more prevalently than their Western counterparts.
Seoul's K-pop gets more press as an instrument of soft-power penetration of North Korea, but Chinese cultural influence is every bit as dangerous for the regime in Pyongyang.
Kim Jong Un has found a middle road in dealing with Chinese economic leverage. Some small amount of investment has been accepted on the margins, but by and large the country has put up a figurative wall against excess Chinese infrastructure or influence penetrating its northern frontier.
China was allowed to provide aid after last September's cataclysmic floods, but no Chinese Army engineers were allowed to build pontoon bridges to besieged North Korean border cities like Musan or Hoeryong. Instead, Kim Jong Un called upon brigades of middle-aged women to pick up displaced railroad ties with their bare hands, working by torchlight. Chinese aid comes with implicit yet distinctive attention to North Korea's own failures.
In 2009, North Korea accepted a de facto "sunshine policy" from the Chinese Communist Party. Bilateral trade was to be expanded radically; new special economic zones were to be set up along the frontier. A huge new bridge was begun between Dandong in China and Sinuiju in North Korea. North Korean business activity in northeast China and province-province economic ties (including to the Chinese province of Jiangsu) were to be expanded. This activity coincided with a spike in coal exports to China.
Today, after an estimated US$300 million of Chinese spending and construction, the new bridge exists, but it sits unused. The dazzling plans and drawings of special economic zones abutting China have largely remained just that - plans and drawings displayed in front of what is still farmland.
The reduction of coal exports to China from North Korea will force some adjustments from Pyongyang but will not bring about wholesale change to the relationship. Steady or even enhanced Chinese enforcement of current sanctions would likely revert relations to where they were a few years ago, prior to Wen Jiabao's meetings with Kim Jong Il, rather than seriously worsening them.
In the meantime, North Korean minerals interests have made a massive amount of money, and coal can be turned more fully to domestic electricity production to feed Kim Jong Un's various new "monumental edifices" in Pyongyang.
China remains a site and conduit of possible interaction between the West and North Korea, and that country's trade with China is probably the greatest source of leverage for political change there.
But we should temper our expectations of a broad strategy that could pull down the North Korean regime.
Pyongyang might be getting the cold shoulder from Beijing, but that has happened before; it would take much more radical, and unlikely, action to shake a country that prides itself on self-reliance regardless of the cost.