
The last few years have witnessed dramatic oscillations in the tenor and substance of the Sino-North Korean relationship. As is well known, the relationship suffered a deep dive in 2017 through to mid-2018 on the back of a number of North Korean missile and nuclear weapons tests — provocations that prompted China to publicly rebuke Pyongyang and even support sanctions against the hermit state. However, North Korean leader Kim Jong Un and Chinese President Xi Jinping have since met on three occasions, and these meetings have been followed by a series of lower level bilateral forums and increases in Chinese aid. The latter developments not only defied trends; they also surprised many well-credentialed analysts whom several month ago concluded that the special, so-called “blood alliance,” or “lips and teeth” relationship between these two neighbors, is no more. How or why did these experts get it wrong?

The notion that China and North Korea no longer share the “lips and teeth” alliance of yesteryear is a theory that had garnered significant currency among Western analysts and some Chinese scholars. However, the Australian National University’s Yu-Hua Chen has argued that “those who think that the relationship has markedly changed didn’t understand it to begin with.” Chen noted that the true meaning of the oft-invoked analogy of “lips and teeth” has nothing to do with ideological or affective closeness (i.e., a “blood alliance”), but rather reflects North Korea’s importance to China as a buffer against the United States and its allies (i.e., “lips” that protect the “teeth” from exposure to the “cold”). In other words, an underlying stability belies the external appearance of volatility in the Sino-North relationship, because the essential foundation of China’s special relationship with Pyongyang is not less-immutable factors such as affective sentiments, but rather a more enduring geostrategic reality.

Chen’s theory reflects a conventional position on Sino-North Korean relations among defense and security analysts. However, this position has its own weaknesses. Foremost among them is the argument that the buffer theory does not tally with China’s reluctance to make strong commitments to defend its “buffer” from foreign (in particular U.S.) aggression. Adam Cathcart noted several years ago that formal Chinese agreements to defend North Korea from nuclear attack are far weaker than those that oblige the United States to defend South Korea and Japan, and that this fact may have motivated the North to step up its efforts to develop an autonomous nuclear deterrent capacity. As the North’s nuclearization accelerated, this commitment appears to have weakened further — for instance, Beijing has recently signaled that it would not defend Pyongyang if the latter attacked another country. There has even been speculation that China may refuse to extend its mutual defense agreement with North Korea (the Sino-North Korean Mutual Aid and Cooperation Friendship Treaty), which is due to expire on 2021.

If geostrategic concerns are the central factor guiding China’s relationship with North Korea, why would China appear reluctant to defend its “buffer” to the hilt? A possible answer to this conundrum can be found in a recent article written by Li Bin, an expert on nuclear proliferation from Tsinghua University’s influential Institute for International Relations. Li noted that China’s protection of, and assistance toward, North Korea has rarely delivered commensurate levels of Chinese political influence over a recalcitrant Pyongyang. The fear for China, thus, is that if it committed to protect Pyongyang “yet could not effectively influence North Korea, then North Korea may act in accordance with the its own security aims, dragging China into military conflict with other countries.” In other words, the buffer imperative may be one reason why China is refusing to commit to defend its neighbor — signing a comprehensive mutual defense agreement may in fact encourage Pyongyang to behave in a way that undermines its role or value as a buffer.

A different but not incompatible explanation for China’s reluctance to offer a stronger mutual defense agreement to Pyongyang has been forwarded by Zhang Liangui, a senior scholar based at the Institute for International Strategic Studies of the Central Party School of the Communist Party of China. For Zhang, the crux of the problem is that North Korea would not want stronger protections in the first place, because it would likely view proposals of this kind — such as offers to extend the protection of a nuclear umbrella — as a means to erode Pyongyang’s autonomy and exert Chinese suzerainty. Zhang points out that many analysts underestimate North Korea’s suspicion that Beijing conspires to subvert its autonomy, and the gravity this concern has in the architecture of North Korea’s political consciousness, culture, and even its constitution. Zhang notes that a core component of North Korea’s much discussed tenet of “self reliance” is the notion of opposing “servitude to great states” (sadae). This has a “concrete meaning in the history of the Korean peninsula” — referring primarily to the Korean Joseon Dynasty’s China policy, and modern North Korea’s founder Kim Il Sung’s battles against the pro-China Yan’an (Yeonan) political faction. Thus for Zhang, any measure that could paint the North as a de facto protectorate of China could imperil the bilateral relationship and encourage, rather than dissuade, North Korean belligerence.

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From this we can conclude that China’s reluctance to commit to the protection of North Korea does not necessarily undermine the buffer argument. Rather, for both Li and Zhang, the reason that Beijing has not offered stronger protections stems from a fundamental conflict between China and North Korea’s views on their relationship. The South Korean Segye Times succinctly captured this dynamic with a recent headline: “China wants to take North Korea into its bosom, while North Korea wants to be self reliant.” On the Chinese side, the buffer function is best served if North Korea (or at least its foreign policy) is subordinate to China in the conventional manner of a protectorate or client state. North Korea, on the other hand, wants to maintain strong autonomy from China. To do so, it may even be willing to sacrifice protections which could enhance its security.

This idea that China’s approach to North Korea’s security is not merely a measure of its commitment to repelling U.S. aggression, but also to a large degree reflects conflicting views on the Sino-North Korean relationship, has the potential to drastically reframe our understanding of both the relationship and Pyongyang’s recent behavior. Chinese scholars have long contended that a major reason that the North has aggressively pursued nuclear weapons is due to Jiang Zemin’s decision to normalize relations with South Korea in 1992 — an act purportedly interpreted by Pyongyang as the sign that its patron/protector had abandoned it. However, if the buffer imperative remains the cornerstone of the Sino-North Korean relationship — and one would assume that Pyongyang would be aware of this should it be the case — this argument loses strength. Perhaps it is not entirely the case that the change in the alliance prompted the North’s nuclearization; perhaps Pyongyang has used nuclearization as a means to alter the terms of the Sino-North Korean relationship in alignment with its own ideals. Put another way, the Kim regime could be staking its role as China’s buffer to leverage China — i.e., to prompt China to continue to invest in the survivability of the Kim regime, while denying Beijing the capacity to translate ongoing support/protection of its buffer into political influence.

This idea is not as fanciful as it may appear. First, it should be noted that Pyongyang’s nuclear program accelerated just as Xi Jinping purportedly demanded that aid to North Korea should start buying Beijing more political/diplomatic clout. It occurred, moreover, while Kim stepped up his efforts to resist Chinese influence — partly through punishing Beijing-friendly officials, such as his uncle Jang Song Thaek, and possibly through ordering the assassination of his Sinophile half-brother Kim Jong Nam. Put another way, the nuclear program accelerated just as the aforementioned contradictions in the China-North Korea relationship had intensified. More importantly, many Chinese experts have since acknowledged that the success of Kim’s weapons programs had subsequently weakened China’s ability to use its military power to leverage Pyongyang, while it has increased Kim’s capacity to harm China diplomatically and strategically.


This last point is significant — it identifies the tools that a nuclearized North Korea could use, and may have used, to leverage Beijing. For instance, some have observed that the nuclear-armed North’s recent bellicosity has re-shifted the “strategic balance” of the region, in that it has prompted the United States and its allies to increase their military capacity in East Asia. This has occurred just as China has heightened its aspirations to gradually establish regional hegemony. Thus, according to respected Chinese historian Shen Zhihua, China is the “real victim” of these developments. As Shen notes:

Think about it. [In response to North Korea’s provocations,] America sent over aircraft carriers etc., including the THAAD system. But could you really say they are directed at North Korea, at protecting South Korea…? I think the intention is more-so that they are directed at China. America is just looking for an excuse to place its fleets on your doorstep. So the result of North Korea’s trouble making is that China is under more pressure and more threatened.

Put another way, North Korea’s bellicosity has given the United States and its allies diplomatic cover to reverse the trajectory of China’s march toward regional hegemony.

North Korea could well want this to occur. Arguably, any increased American/allied military presence in China’s neighborhood makes the maintenance of China’s North Korean buffer more essential to China’s security, and more pressing. In particular, it makes the immediate collapse of the Kim regime a larger security problem for China. Theoretically speaking, such a development could have cornered China into continuing to invest in the stability of the recalcitrant Kim regime, at the very time Beijing was reappraising the value of continuing the alliance. This would moreover weaken China’s position to demand a political return for supporting Pyongyang — i.e., it could allow Pyongyang to avoid sadae.

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This argument is strengthened when we consider the likely impact China’s achievement of regional hegemony would have upon the Sino-North Korean relationship. Chinese Asian hegemony implies the creation of a pan-Asian buffer. This would render the North Korea buffer redundant. A nonaligned Pyongyang, under these circumstances, would have few tools at its disposal to resist Chinese pressure or control. Indeed, given the raft of problems in the Sino-North Korean relationship in recent years, a hegemonic China may even consider the very survival of the recalcitrant Kim regime to be undesirable. Shen, for instance, has called North Korea a “potential enemy” of China, and Oriana Skylar Mastro has reported that such a view is widespread among Chinese political and military elites. Hence, there are thus a number of reasons why North Korea would want to invest in a “regional rebalancing” — even if it runs the risk of tilting the balance of power in the favor of its former enemy, the United States.

The leverage theory makes up for shortcomings in the buffer theory. It also has some explanatory power for interpreting Pyongyang’s recent, ostensibly self-endangering belligerence. What is more, the same paradigm can interpret Pyongyang’s more recent diplomatic actions — in particular, its pledges to de-nuclearize, and to reach out to its old foes, the United States and South Korea.

A common interpretation of Pyongyang’s motive for reaching out to the West has been a desire to “hedge” against China — i.e., to avoid economic overreliance over its neighbor. However, this argument has problems. Firstly, Western aid to North Korea would almost certainly be accompanied with demands for wholesale political reform, which the North would almost certainly find unpalatable. South Korea has proven a less demanding benefactor in this regard. However, Seoul’s largesse is dependent on a capricious domestic political environment, and frustration with Pyongyang has thus far led to a semi-regular oscillation between sunshine and hardline policies. Russia is another potential benefactor. However, its incentive to invest in the survival of Pyongyang for its own sake is less than is the case for China.

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This leads us back to the paradigm of asymmetric leverage. Kim’s first meeting with Xi Jinping came soon after the confirmation of Kim’s meeting with U.S. President Donald Trump. As with subsequent meetings, it was followed by a boost in Chinese aid and trade to the hermit state. China has marketed these developments as rewards for preliminary movements toward denuclearization. However, China’s actions could well have been motivated by the threat that North Korea could potentially “realign” with China’s geopolitical and regional rivals. Such a fear may seem absurd, but it would not be unprecedented. Mao Zedong once famously expressed concerns that Kim Il Sung could turn his back on the communist alliance, and even compared Kim with Imry Nagy, the Hungarian politician who supported the so-called Hungarian Uprising against the Soviets in 1956.

Kim Jong Un may not be Imry Nagy, but his relationship with China has been just as problematic as it was for his grandfather. To the extent that North Korea believes that China harbors such fears, it could well be tempted to manipulate ambiguity about the new relationship with the United States and South Korea to coax China to be a more generous and less demanding benefactor.

In light of the above, the notion that “asymmetric leverage” exists in the Sino-North Korean relations is useful for interpreting the recent behavior of both China and North Korea. In the case of the former, it explains the recent reversal of China’s diplomatic posture toward Pyongyang. In the case of North Korea, it gives a new angle on the so-called “madman” theory in relation to Kim Jong Un. For Pyongyang, marked asymmetries in military, economic, and diplomatic capital means that other than the North’s value to China as a buffer, the Kim regime has few other resources at its disposal to resist Chinese influence. However, in the final analysis, China’s buffer is the Kim regime (or any North Korean regime hostile to Western influences). A leverage strategy based on staking China’s buffer must thus involve putting the very existence of the Kim regime on the table. What is more, the risks of this strategy have perhaps been overstated. If the presumption is that China will in the final analysis move to protect its buffer, Pyongyong has considerable room to maneuver; it knows that while Beijing may be angered by THAAD installations south of the 38th parallel, it would never countenance their presence on the southern banks of the Tumen.


The above analysis leads to a somewhat pessimistic appraisal of the future of Sino-North Korean relations, and the future direction of North Korea’s foreign policy. As long as the North continues its hold “self-reliance” as a core and immutable political tenet, and as long as this stands in defiance of China’s plans for regional hegemony, one can expect Pyongyang’s cycle of threats and reconciliation to continue. This could potentially be resolved if the United States and China announce a united front against Pyongyang — but competition for regional hegemony, and South Korea’s aspirations for peaceful unification, make this difficult.

Another mitigating variable could, perversely, come from Xi’s success in removing the time limits of his tenure. Xi’s rule could extend through many cycles of North Korean hostility and supplication; however, it is less likely that his patience will do the same.

Corey Bell has a Ph.D. in Asian Studies from the University of Melbourne in Australia. He is currently based in South Korea.