Table of Contents

Chinese Understandings of Strategic Stability

There has been a long international debate about how to define and understand the term “strategic stability.”1 In the case of China, strategic stability is not a new term. Over the past few decades, the People’s Daily—the most important official newspaper in China—has published commentaries and editorials that touch upon the issue of strategic stability.2 However, the traditional Chinese understanding of strategic stability is not completely in line with Western perspectives. The Chinese have traditionally taken a much broader view of strategic stability that encompasses not only nuclear relations but also political-military relations more generally.3 They have referred to strategic stability as a general state of balance—including military, alliance, and economic stability, and other dimensions.4 This very general and abstract approach toward strategic stability has been a major obstacle to Chinese experts and their Western counterparts trying to precisely understand each other’s nuclear policies.

Tong Zhao
Tong Zhao is a senior fellow in Carnegie’s Nuclear Policy Program based at the Carnegie–Tsinghua Center for Global Policy.

When China’s nuclear and strategic communities were introduced to Western literature on deterrence and strategic stability, they found the Western analytical framework useful in academic and policy research and began to incorporate it into China’s domestic discussions. Since then, Chinese analysts have written and published a relatively large number of papers to apply and promote the new analytical framework for understanding nuclear stability. These authors include experts from nuclear defense industry,5 the military,6 the foreign ministry’s research institutes,7 think tanks,8 and university research centers.9

Today, although there is still debate about the precise definitions of certain terms,10 many Chinese analysts are comfortable examining the security implications of specific nuclear policies by looking at their potential impact on crisis stability and arms control stability—the two main components of strategic stability in Western literature.11 As these concepts are accepted and embraced by a wider circle of policymakers and academic analysts, more Chinese experts are using them to study the security implications of new military developments—both in the United States and elsewhere—on Chinese nuclear deterrence and regional stability, including the impact of missile defense on nuclear relationships.12 In previous debates on deep nuclear reductions, Chinese experts have also used these concepts to formulate policy recommendations and to explore how strategic stability will change as global nuclear stockpiles continue to decrease.13

Chinese nuclear experts view the maintenance of a secure second-strike capability as the cornerstone of China’s deterrent and the fundamental guarantee of national security. Accordingly, China appears fully committed to maintaining a mutual vulnerability relationship with its nuclear rivals,14 and views it as a necessary condition for achieving strategic stability.15

After this narrower concept of strategic stability was accepted by the Chinese nuclear community, it began to be incorporated into official Chinese rhetoric. Starting in the late 2000s, Chinese official statements and documents began to refer to strategic stability in the same manner.16

Although many experts in China’s nuclear community have embraced the narrow definition of strategic stability prevalent in the West, they generally do not like to equate the type of strategic stability employed by United States and China to the relationship between the United States and Russia. The U.S.-Russia dynamic implies a Cold War–style strategic rivalry, whereas Chinese experts believe the U.S.-China strategic relationship is far from being entirely adversarial. They also point out that U.S.-Russia strategic stability is based on a general balance of military power that includes nuclear weapons. In comparison, there is considerable disparity between the nuclear capabilities of the United States and China.17

Some Chinese scholars have also questioned certain aspects of and proposed ways to improve the Western definition of strategic stability. For example, Li Bin and Nie Hongyi from Tsinghua University suggest that the existing definition of strategic stability does not include other important elements that also have implications for crisis stability and arms race stability. They argue that strategic stability should involve four elements: in addition to the two elements included in the prevalent definition—crisis stability and arms race stability—they include the firmness of nuclear taboo and strategic mutual confidence and communications. They point out that nuclear taboo and strategic communications also have important influence on crisis stability and arms race stability but have not been incorporated into existing definitions in the Western literature.18

Arms Race Stability

China’s leaders place a high degree of importance on the credibility of China’s nuclear deterrence, but China has not traditionally had a robust analytical framework to answer the question of “how many is enough.” China’s top leaders intended to build a “lean and effective nuclear force” but did not explain what this meant in practice.19 Mao Zedong, for example, had the perception that only a few nuclear weapons would be necessary to deter the United States from using nuclear weapons against China. In recent decades, however, the Chinese nuclear community has started to adopt the concept of mutual vulnerability from Western literature, using it to understand qualitative and quantitative requirements for Chinese nuclear capability. Concepts such as the threshold of unacceptable damage have been used to examine the numerical requirement for Chinese nuclear force development.20

Drawing mostly on the U.S. framework, Chinese experts have also conceptualized the credibility rationale behind China’s nuclear development and force posture. They have illustrated the role that “first-strike uncertainty” plays in China’s nuclear deterrence and pointed out potential areas in China’s nuclear development and operation that could be more transparent.21 It is argued, for instance, that as China deploys more road-mobile missiles, it does not need to rely heavily on numerical ambiguity to obtain a high level of survivability. Instead, China could rely more on geographical ambiguity. It is also suggested that China could be more transparent about mid-level (more operational) nuclear doctrines that would give outsiders a deeper understanding of the guiding principles of Chinese nuclear posture without revealing sensitive details of Beijing’s nuclear operations.

With that said, China’s confidence in its second-strike capability faces increasing challenges from new military technologies. During the Cold War, whether mutual vulnerability existed between the two nuclear rivals could be relatively easily determined by modeling various nuclear exchange scenarios to see if sufficient nuclear weapons would survive after absorbing a nuclear first strike. Strategic missile defense was limited by the Anti-Ballistic Missile Treaty (ABM) and therefore did not significantly affect the nuclear calculations until toward the end of the Cold War. In comparison, today’s nuclear equation is much more complex. Long-range missiles have become increasingly accurate and are now capable of conducing counterforce strikes with small-yield nuclear warheads that do not generate substantial collateral damage. Technologies—such as the burst-height-compensating super-fuze and advanced computer codes that can quickly compensate for failed missile launches during a disarming strike—contribute greatly to the United States’ capability to execute a nuclear first strike.22 Furthermore, nuclear weapons are no longer only vulnerable to nuclear strikes, but also a wide range of non-nuclear military capabilities that could potentially threaten the survivability of nuclear weapons. Conventional prompt-strike weapons, for instance, are potentially capable of striking mobile missile vehicles and nuclear command and control systems. Advanced space-based surveillance and reconnaissance assets further enhance the capabilities of conventional precision strikes. The possibility of using sophisticated cyber attacks to undermine nuclear command and control systems and to disable missile launches also add to one’s concern about the reliability of second-strike capability. On top of that, advanced missile defense technologies are becoming available and can further neutralize the effectiveness of any survived nuclear retaliatory capabilities. China has to include all of these new technologies in its calculations to evaluate the existence of the mutual vulnerability relationship between itself and its nuclear rivals.

In the case of missile defense, existing technologies face major challenges, such as the inability to reliably distinguish real warheads from decoys and chaffs, as well as the difficulties imposed by saturation attacks. U.S. officials point to the technical limits of the existing missile defense systems and the small stockpile of currently deployed interceptors as hard evidence that U.S. missile defense poses no real threat to China’s nuclear deterrent. However, what worries China is the perceived possibility that future development of missile defense technologies could achieve rapid breakthroughs and quickly become much more effective and efficient than existing systems. Such concerns are not totally unreasonable. For instance, the U.S. Missile Defense Agency’s recent investment into developing the so-called Multi-Object Kill Vehicle may radically improve the United States’ missile defense capability in the future.23 Sudden technological breakthroughs like this are not completely predictable and do not always leave sufficient time for rival countries to adopt countermeasures. As a result, such uncertainties make it almost impossible for Washington to reassure Beijing about the innocuousness of its missile defense.

Geographical reality further complicates the situation. China is located right next to North Korea, and the United States has a policy of developing and deploying missile defense to protect itself and its allies from North Korean missile threats. However, given the geographical proximity between North Korea and China, any U.S. strategic missile defense system that can intercept North Korean intercontinental ballistic missiles (ICBMs) launched at the continental United States would likely also be capable of engaging Chinese ICBMs, especially if Chinese ICBMs are deployed in or close to the northeast part of the country. In addition, the numerical gap between the stockpiles of North Korean and Chinese ICBMs may be narrowed if North Korea quickly builds up its ICBM forces in the future. Currently, China is believed to possess between forty-five to fifty-three ICBMs.24 North Korea has publicly shown that it possesses at least several KN-08 and KN-14 ICBMs, although North Korean ICBMs haven’t been successfully flight tested to the extent of their range. China’s view has always been that only a small portion of its ICBMs would survive a first strike. In this case, the number of survivable Chinese ICBMs may be similar to that of North Korean ICBMs. Therefore, it would be very difficult, if not impossible, for the United States to deploy a strategic missile defense system that threatens only North Korea but not China.

To address the threat posed by missile defense to the U.S.-China nuclear relationship, a Chinese expert once proposed that the United States commit to a qualitatively and quantitatively limited missile defense system in return for China putting a cap on its nuclear stockpile.25 This proposal was turned down by both Chinese and U.S. experts. One important reason was that it would be very difficult for both actors to agree on what would constitute reasonable respective limits on each side because of dramatically different perceptions about the impact of U.S. missile defense on Chinese nuclear deterrence.

This is just one example of how a single additional variable—missile defense—in the nuclear equation could greatly complicate relevant players’ calculations and make it exponentially more difficult for them to agree on what a mutual vulnerability relationship should look like, due to the very different compositions of and various uncertainties associated with their respective strategic capabilities. Today, nuclear weapon states may have to take all relevant variables into consideration, including conventional prompt-strike weapons, advanced space-based surveillance and reconnaissance capabilities, offensive cyber capabilities, and counterspace weapons, among others. All these new and non-nuclear capabilities can, in one way or another, affect the survivability and effectiveness of nuclear weapons and are therefore drawing serious concerns from usually very risk-averse nuclear planners and strategists. The key question is whether it is feasible for nuclear weapon states to continue relying on the maintenance of mutual vulnerability relationships as the basis for strategic stability. So far, China seems very much committed to maintaining a highly survivable and reliable second-strike capability into the long-term future, despite all potential challenges posed by new technologies. Given the increasing difficulty of reaching common understandings between nuclear rivals on how to maintain mutual vulnerability, nuclear weapon states—including China—will likely develop their strategic capabilities based on their own understanding and predictions of future balances of capabilities across multiple domains. The result may be an intensified security dilemma and arms race.

Crisis Stability

Crisis stability was not something China’s traditional security thinking focused upon. Ancient Chinese military thinking did not touch upon the issue of crisis or escalation management. During China’s revolutionary years under Mao Zedong, China’s security policy emphasized the importance of using tactics that create the utmost uncertainty in the enemy’s mind. The intent was to understand the enemy as much as possible but to keep the enemy from obtaining a similarly accurate understanding.26 This traditional thinking was very different from the West’s emphasis on reducing the fog of war.

Chinese political and military leaders consistently expressed the view that military actions should only be taken when there is absolute certainty (or near-absolute certainty) of winning. Among the three principles for fighting enemies stressed by Mao Zedong, one was about when to employ military power: “[It] is the winning principle. We either do not fight them; or if we do choose to go into a fight, we must win. We should never fight a war for which we are not very well prepared and which we do not have full confidence of winning.”27 Because of this principle, Chinese strategists traditionally did not devote a great deal of thinking to scenarios other than complete victory or defeat.

Under the leadership of Mao Zedong and Deng Xiaoping, there was a very clear line in Chinese military doctrine and policy deliberation between the roles of nuclear weapons and conventional weapons. Nuclear weapons were regarded only as a “strategic deterrent” for deterring nuclear wars. They were not intended and not very useful, Mao Zedong and Deng Xiaoping believed, for deterring other types of wars, including large-scale conventional wars and regional conflicts.28 They believed that mass mobilization (the people’s war) was more effective in deterring large-scale conventional invasion, and rapid-response conventional forces were more effective at deterring regional conflicts.29

In addition, China was not a major player in previous nuclear crises, which might have contributed to China’s lack of appreciation of inadvertent escalation risks. Before the 1980s, Chinese discussions focused on how most crises stemmed from domestic struggles rather than international problems.30 Since China obtained nuclear capability in the mid‑1960s, it has had little direct involvement in nuclear crises, with a slight exception in 1969 when the Soviets were reported to have implicitly threatened a surgical strike against China’s rudimentary nuclear capability.31 In contrast, the United States and the Soviet Union underwent a number of serious nuclear crises, not least the Cuban missile crisis. These nuclear crises between the United States and the Soviet Union taught them firsthand lessons about the real dangers of inadvertent escalation, whereas China had very limited experience in comparison.

Moreover, the traditional Chinese view was that discussing the issues of crisis or escalation control in and of itself sends a signal of weakness.32 Never making compromises with the enemy was regarded as a sacred principle and a key quality of a decisionmaker.

Gradually, the gap between U.S. and Chinese understandings about crisis stability has narrowed, as China becomes more appreciative of escalation risks. During various U.S.-China Track II dialogues, Chinese participants have become more interested in discussing escalation prevention from the conventional to nuclear level.33 Specific escalation scenarios across the Taiwan Strait were mostly discussed during these exchanges, but as the conversation went broader and deeper,34 other scenarios—such as on the Korean Peninsula, in the South China Sea, and in South Asia—were also discussed.35 Chinese participants have started to appreciate the risk of inadvertent escalation if signals are miscommunicated.36 They have begun to urge Washington and Beijing to make crisis management a priority and seek mutual understanding of each other’s key operational principles, and to stress that both countries must establish bilateral crisis management mechanisms to improve communication both before and during a crisis.37 The importance of direct communication is also increasingly emphasized.38

During such exchanges, Chinese participants have been increasingly open and willing to discuss more sophisticated issues related to crisis management. On several occasions, the issue of cross-domain escalation was discussed. Escalation control discussions expanded beyond nuclear-only scenarios, including additional domains such as space, air, and cyber. Chinese experts also actively argued for the two countries to establish “rules of the road” to manage potential crises.39

The same trend has appeared in the Chinese nuclear community’s publications. They increasingly accept U.S. scholars’ concepts and use their works to draw lessons for China’s nuclear policy. Chinese scholars introduce and apply concepts such as Thomas Schelling’s “threat that leaves something to chance,” Robert Jervis’s slippery slope from conventional to nuclear war, and Glen Snyder’s stability/instability paradox to Chinese scenarios.40 Experts such as Wang Jisi and Xu Hui have proposed practical steps for China to take in order to better understand and manage crises.41

However, there are still important misunderstandings within the U.S. nuclear community about China’s crisis management policy. U.S. analysis of the People’s Liberation Army (PLA) Rocket Force’s nuclear operation still relies heavily on very few publications available written by Chinese military scholars, which have generated a number of major misunderstandings. On the issue of crisis management, for example, the book Science of Second Artillery Campaigns, published by the PLA Rocket Force (formerly the Second Artillery Force) in 2004, discusses situations in which China might need to “lower the nuclear deterrence threshold.” This was interpreted by U.S. experts as evidence that China was prepared to use nuclear threats to deter conventional wars or in scenarios of conventional conflicts.42 But what the book really means by referring to “lowering the nuclear deterrence threshold” is raising the alert status during a crisis rather than using nuclear weapons in scenarios other than a retaliatory strike.43 Similar misunderstandings took place over terms used by the Rocket Force such as “conventional war under nuclear deterrence” or “double deterrence.”44 In recent years, U.S. and Chinese experts managed to work out many such differences by jointly producing and promoting a common glossary on nuclear issues.45 However, some of the misunderstandings caused by linguistic, cultural, and bureaucratic factors continue to exist and will take time to be resolved.

New military technologies can pose fresh challenges for crisis management in the future. For instance, U.S. and Chinese experts have not reached common understandings about whether the use of counterspace (such as antisatellite) weapons could cause serious escalation risks. Some Chinese experts seem to believe that China could consider using antisatellite (ASAT) weapons in the early phase of a regional conventional conflict against U.S. early-warning satellites. Besides providing early warning for U.S. strategic nuclear forces, these satellites also help enhance U.S. theater ballistic missile defense capabilities. By taking out some of these satellites, China can maintain the efficacy of its conventional tactical missiles, which play an important role in Chinese military strategies in future regional conflicts—including one over the Taiwan Strait. Nonetheless, Washington is likely to view an ASAT attack against its early-warning satellites not as a tactical move but as a major escalation.46 Such divergent views could cause misunderstandings and inadvertent escalation.

Similarly, the United States’ emerging interest in using cyber weapons to undermine an enemy or competitor’s nuclear command, control, and communication (NC3) system as part of the so-called left-of-launch missile defense strategy introduces unprecedented risks of inadvertent escalation. Knowing that the United States might have been developing covert cyber and electronic warfare capabilities to infiltrate and interfere with China’s nuclear NC3 system, Chinese decisionmakers would face extra pressure to act quickly during a crisis. If such interference were detected during a crisis, it is very likely that China would not be able to figure out quickly and exactly what damage might be done to its NC3 system or what the strategic intention would be. If China feels that it has to assume the worst and act quickly before its NC3 system is completely undermined, an unnecessary nuclear escalation would be more likely to happen than before. So far, there has not been serious discussion on such matters between the two governments.

Japan’s Impact on U.S.-China Strategic Stability

The troublesome Chinese-Japanese security relationship further complicates the U.S.-China nuclear dynamic. Problems in Chinese-Japanese relations derive partly from deeply buried historical antagonism, which gets evoked each time senior Japanese officials pay tribute to the Yasukuni Shrine or right-wing Japanese officials appear to deny responsibility for crimes committed during World War II. Bilateral security tensions are also fueled by territorial disputes, mostly over the Senkaku/Diaoyu Islands. Extended confrontations over the disputed islands have diminished bilateral trust and reduced public perception to historically low favorability levels. Rising nationalist sentiments add fuel to the tension. Leaders from both countries find it difficult to initiate high-level visits and exchanges. On top of that, Japan faces increasingly intensive competition between the United States and China. It has given China the impression that it is pessimistic about the prospect of repairing relations and has decided to side completely with the United States to hedge against a rising China. Beijing, therefore, is increasingly showing a cold shoulder to Tokyo. As the U.S.-China relationship continues to face constant troubles, China sees the ever-closer U.S.-Japan security alliance increasingly as a strategic threat.47

Nuclear Hedging and U.S. Extended Nuclear Deterrence

Besides concerns over the general trend of Japan’s military growth and normalization, China shows real unease about Japan’s nuclear hedging capability. Regarding material capability, Japan is the only non-nuclear-weapon state under the Nuclear Non-Proliferation Treaty that has both commercial-scale reprocessing and enrichment capability. Japan’s large plutonium stockpile draws China’s close attention, and many Chinese experts attribute this large plutonium stockpile to a deliberate policy choice rather than problematic planning and mismanagement by Japan’s cumbersome civilian nuclear bureaucracy. Furthermore, Japan’s M-V and H-II rockets have the potential to deliver a heavy nuclear payload over long distances. Japan has also demonstrated the capability to retrieve unmanned spacecraft and the upper stage of an H‑IIB rocket48—technology that could be useful in building nuclear warhead–reentry vehicles.

Many Chinese experts suspect that Japan is deliberately pursuing a strategy of nuclear hedging. Secret studies conducted by the Japanese government during the Cold War recommended against a nuclear weapon program but argued for accumulating dual-use technologies useful for obtaining a virtual military nuclear capability. Senior Japanese officials’ open remarks about nuclear hedging have reinforced Chinese concerns.49

As a result, China acknowledges that the U.S. extended nuclear deterrence over Japan helps contain the latter’s nuclear ambition and contributes to nuclear nonproliferation in the region. As North Korea’s nuclear and missile capabilities advance, rising voices in Japan are calling to develop Japanese offensive long-range strike capabilities against enemy military bases. If the United States fails to reassure Japan about the reliability of its extended deterrence, the chances of Japan going nuclear might further increase.

However, despite Washington’s longstanding policy of nonproliferation, there have been recent cases of U.S. scholars openly arguing for Japan to develop its own nuclear deterrent.50 U.S. President Donald Trump’s remarks on the possibility of Japan going nuclear have also made some Chinese analysts question the United States’ commitment to maintaining regional stability through promoting nonproliferation. Besides Japan’s own nuclear potential, Chinese experts worry that Japan might undermine U.S.-China strategic stability in several other ways.

Japan’s Potential Contribution to U.S. First-Strike Capability Against China

The first concern is that Japan may work together with the United States—deliberately or not—to undermine China’s strategic nuclear deterrent vis-à-vis the United States. Even though China has been gradually modernizing and slowly expanding its nuclear arsenal in recent decades, there is still debate about whether it has achieved assured nuclear second-strike capability against the United States. Some U.S. scholars believe Chinese nuclear forces are still vulnerable to a U.S. first strike.51 Chinese scholars point out that although Chinese nuclear retaliation capability against the United States is uncertain, Beijing is working hard to minimize the remaining uncertainty.52 China’s recent moves to field more capable road-mobile intercontinental ballistic missiles and introduce sea-based nuclear weapons are clear signals that, ultimately, China wants to eliminate any uncertainty by acquiring an assured second-strike capability vis-à-vis the United States. The Chinese efforts to achieve this goal, however, can be undermined by Japan’s military cooperation with the United States.

China’s greatest concern about its future nuclear deterrent is the U.S. missile defense system, which has received persistent investment and achieved sustained improvement. Japan has been incorporated into the U.S. missile defense network in Asia through joint development and deployment of SM-3 interceptors on Aegis ships. It already hosts two AN/TPY-2 X-band radars and is further considering introducing land‑based SM-3 systems and the Terminal High Altitude Area Defense (THAAD) batteries. China worries that advanced SM-3 interceptors may have the potential to engage Chinese ICBMs in the future.53

Japan sees great political value from such missile defense cooperation with the United States, which “symbolizes the Japan-U.S. alliance.”54 China’s concern is that such cooperation is at least partially targeted at itself. U.S. experts and officials acknowledge that Washington needs to develop a regional missile defense network in the Asia-Pacific to counter China’s conventional missile capabilities.55 However, such capabilities to defend against China’s conventional ballistic missiles could also neutralize China’s theater nuclear missiles, which would be useful for retaliating against U.S. targets in the region. As a former senior U.S. official commented, regional ballistic missile defense “enables offensive operations to begin at a time of our choosing rather than the enemy’s, and raises the scale of attack that an attacker must attempt if it wants to overwhelm the defense.”56 China, therefore, worries that Japan’s contribution to the U.S. regional missile defense network increases the United States’ first-strike capability against China.

In addition, China is putting together a fleet of nuclear strategic ballistic missile submarines (SSBNs) and having them conduct patrols. Part of China’s motivation for building this fleet seems to be the perceived capability of SSBNs and submarine-launched ballistic missiles (SLBMs) to penetrate existing U.S. missile defense systems.57 However, U.S. regional allies, especially Japan, have been working closely with the United States to enhance anti-submarine warfare (ASW) capabilities in the Asia-Pacific, which poses a major threat to China’s sea-based nuclear deterrent. Japan’s participation in the U.S. ASW network is of particular concern to China. If Chinese SSBNs are to conduct patrols in the West Pacific, they will have to pass through water channels along the so-called First Island Chain and some of the most important water channels are immediately adjacent to Japan-controlled territories. Therefore, Japan is in a strategically advantageous position to help the U.S. Navy track, trail, and even disrupt Chinese SSBNs on their patrol routes. In recent years, Japan has worked with the United States to upgrade the underwater sound surveillance system that the United States first deployed during the Cold War.58 With the most formidable ASW capability in the region, Japan participates frequently in joint ASW training, exercises with the U.S. Navy, and sends anti-submarine reconnaissance aircraft to fly over the South China Sea.59 Given that a major portion of China’s SSBN fleet is presumed to be deployed in the South China Sea, Japan’s increasing ASW operations over that area constitute a significant and increasing threat to China’s nuclear deterrent.60

Japan’s Potential Interest in U.S. Nuclear Primacy

From the Chinese perspective, Japan may have an interest in undermining U.S.-China strategic stability. Some U.S. scholars hold the view that the United States needs to possess nuclear primacy (nuclear first-strike capability) over China in order to bolster its own deterrence posture and enhance the credibility of the U.S. extended nuclear deterrence for allies.61 The argument is that if there is mutual vulnerability between Washington and Beijing, the United States may be deterred from launching a nuclear retaliation after China strikes Japan with nuclear weapons. This view may be shared by some Japanese experts. Japan is also very concerned that a mutual vulnerability relationship between Beijing and Washington would effectively reduce the danger of conventional conflicts escalating to the nuclear level. Thus, Japan worries that a stable U.S.-China nuclear relationship would embolden China’s conventional military aggression toward Japan.62 Partially because of Japanese concern over the so-called stability-instability paradox, the administration of former president Barack Obama decided not to openly acknowledge the existence of a mutual vulnerability relationship with China.63

Japan is also believed to have played a role in discouraging Washington from adopting a no-first-use declaratory policy and from announcing that the “sole purpose” of its nuclear weapons is to deter nuclear attack. According to the Center for Global Security Research’s Brad Roberts, the Obama administration’s nuclear posture review report rejected the “sole purpose formulation” after “carefully considered the views of its allies in Northeast Asia (and elsewhere).”64 The Obama administration also seriously considered adopting a no-first-use policy in 2016 but decided not to do so at the last minute “largely because of pushback from allies who are under the U.S. nuclear ‘umbrella.’”65 It was reported that Japanese Prime Minister Shinzo Abe personally conveyed concerns about a U.S. no-first-use policy to U.S. Admiral Harry Harris, commander of the U.S. Pacific Command.66

From the Chinese perspective, declaring that the “sole purpose” of nuclear weapons is to deter nuclear attacks and adopting a no-first-use policy of nuclear restraint are the most effective ways to reduce nuclear risks and promote nuclear disarmament. Therefore, China sees Japan’s efforts to prevent the United States from taking such measures as undermining U.S.-China strategic stability and regional security.

Japan’s concern about an unfavorable conventional military balance in East Asia has only increased in recent years, as Beijing is quickly catching up to—and may even be outpacing—Japan’s conventional military capability development. China is also narrowing the gap with U.S. conventional capability in the region. This could have implications for Japan in a future military conflict over the Senkaku/Diaoyu Islands or the Taiwan Strait. Even some U.S. scholars worry that China may obtain conventional military superiority vis-à-vis Japan and the United States in some restrained regional theaters in the near future. A 2015 RAND report on the U.S.-China military balance, for instance, points out that “PLA forces will become more capable of establishing temporary local air and naval superiority at the outset of a conflict,” which “might lead Chinese leaders to believe that they could deter U.S. intervention in a conflict between it and one or more of its neighbors.”67

In anticipation of possible Chinese conventional superiority in the future, some scholars in the United States have argued for reemphasizing the role of nuclear weapons—especially the so-called tailored nuclear capabilities that can be employed more flexibly on the battlefield.68 Some suggest that the United States may need to consider using nuclear weapons first during a conventional war with China in the future.69 Some others predict that the United States’ Asian allies, such as Japan, should consider their own nuclear options.70 Therefore, concerns about conventional imbalance may have direct implications for nuclear stability. The propositions for maintaining or even increasing the role of nuclear weapons could undermine international efforts to promote nuclear arms control. Japan and other U.S. allies have already voted against the starting of negotiations at the United Nations on a treaty to ban nuclear weapons. Increasing concern about conventional imbalance could seriously challenge U.S.-China strategic stability and regional security in the future.


Although China has gradually embraced the Western definition of strategic stability, U.S.-China relations face serious related challenges. In particular, new military technologies complicate China’s confidence in its second-strike capability vis-à-vis the United States. Efforts to address these challenges have led to further nuclear modernizations and contributed to an increasingly blurred line between nuclear and conventional capabilities. The generally adversarial relationship between China and Japan further complicates the U.S.-China strategic stability relationship. Although the U.S. extended nuclear deterrence helps contain Japan’s aspirations for its own nuclear deterrent capability and therefore contributes to regional nonproliferation, such constraint might be eroding as a result of the Trump administration’s lukewarm commitment to the alliance. More importantly, Beijing believes that Tokyo has an inherent interest in helping the United States obtain nuclear primacy over China and in undermining U.S.-China nuclear stability in order to strengthen the reliability of U.S. extended deterrence and contain China’s conventional military capability. A perceived shift in the region’s conventional military balance has exacerbated Japan’s concerns over time and poses a growing challenge to U.S.-China strategic stability. So far, confidence-building measures on nuclear issues are limited between Washington and Beijing and between Beijing and Tokyo. Official U.S.-China nuclear dialogue may help improve mutual understanding, and Chinese-Japanese security exchanges can play a critical role in mitigating threat perceptions. Some form of trilateral discussions could also go a long way to promote positive interactions among the three countries and contribute to strategically stable relations.

About the Author

Tong Zhao is a fellow in Carnegie’s Nuclear Policy Program based at the Carnegie–Tsinghua Center for Global Policy. His research focuses on strategic security issues, including nuclear arms control, nonproliferation, missile defense, strategic stability, and China’s security and foreign policy.


1 See, for example, John D. Steinbruner, “National Security and the Concept of Strategic Stability,” Journal of Conflict Resolution 22, no. 3 (September 1978); Elbridge A. Colby and Michael S. Gerson, Strategic Stability: Contending Interpretations (Carlisle, PA: Strategic Studies Institute, U.S. Army War College, 2013).

2 Xinhua News Agency, “NATO Foreign Affairs Ministers Conference Emphasized Defense Issues—Arguing for Capabilities That Can Deter Invasion and Resist Pressure” [in Chinese], People’s Daily, December 9 1977.

3 Brad Roberts, “China and Ballistic Missile Defense: 1955 to 2002 and Beyond,” Institute for Defense Analyses, September 2003.

4 See, for example, Wang Jin and Li Wensheng, “The Controversies Over the Two-Plus-Two: The Missile Defense and Strategic Weapons of the Untied States and Russia” [in Chinese], Ordnance Knowledge, no. 5 (2008); Xu Nengwu, “The Threats and Challenges to Outer Space Security Posed by the Adjustment of the U.S. Strategic Deterrent System” [in Chinese], National Defense Science & Technology, no. 2 (2013).

5 Sun Xiangli, “Theories and Practice in Arms Control” [in Chinese], Teaching and Research, no. 6 (2001).

6 Li Jingping, “A Preliminary Analysis on U.S.-China Strategic Stability: Contructing U.S.-China Strategic Stability Beyond Strategic Weapons” [in Chinese], in 13th PIIC Beijing Seminar on International Security (Beijing: Program for Science and National Security Studies, 2012).

7 Lewis A. Dunn et al., “Building Toward a Stable and Cooperative Long-Term U.S.-China Strategic Relationship” [in Chinese], Science Applications International Corporation, the Pacific Forum CSIS, and China Arms Control and Disarmament Association, 2012.

8 Xu, “Outer Space Security.”

9 Wu Ting, “Space Weaponization From the Perspective of U.S.-China Strategic Stability” [in Chinese] (master’s thesis, Fudan University, 2012); Li Deshun, “The Mutual Independence in Strategic Stability” [in Chinese] (PhD dissertation, Tsinghua University, 2012); Li Bin and Nie Hongyi, “Analysis on the Strategic Stability Between China and the United States” [in Chinese], World Economics and Politics, no. 2 (2008): 13–19.

10 James M. Acton, “Reclaiming Strategic Stability,” in Strategic Stability: Contending Interpretations, ed. Elbridge A. Colby and Michael S. Gerson (Carlisle, PA: Strategic Studies Institute, US Army War College Press, 2013).

11 Wu Riqiang, “Survivability of China’s Sea-Based Nuclear Forces,” Science & Global Security 19, no. 2 (July 2011); Li Bin and Wu Riqiang, “Impact of Euro-Missile Shield on Russia Security” (paper presented at the the 19th International Summer Symposium on Science and World Affairs, Oslo, Norway, July 21–30, 2008); Lora Saalman, “China and the U.S. Nuclear Posture Review,” Carnegie Endowment for International Peace, February 28, 2011,

12 Li Hongbo and Zhou Yan, “Indian Missile Defense Plan and South Asia Regional Security” [in Chinese], South Asia Studies, no. 4 (2009); Liu Huaqiu, “International Arms Control Aces New Challenges—‘Arms Control and Disarmament Handbook’ Editor Interviews” [in Chinese], Modern Military, no. 5 (2001).

13 Xu Nengwu and Jin Saimei, “The Practicality of the Construction of a Nuclear Free World” [in Chinese], Contemporary World, no. 1 (2010): 64–66; Li Bin and Xiao Tiefeng, “Rethinking the Role of Nuclear Weapons” [in Chinese], Foreign Affairs Review 3 (2010): 3–9.

14 In many cases, Chinese experts use the term “mutual vulnerability” interchangeably with the term “mutually assured destruction” (MAD). In the English literature, MAD can refer to a more symmetric balance of capabilities, but for most Chinese analysts, a mutual vulnerability relationship between a strong nuclear state and a weak nuclear state is also a type of MAD relationship. The two terms are therefore not clearly distinguished in the Chinese literature.

15 Li Bin, “Identifying China’s Nuclear Strategy” [in Chinese], World Economics and Politics, no. 9 (2006): 16–22.

16 “Nuclear Disarmament and Reduction of the Danger of Nuclear War: Working Paper Submitted by China” (presented at the 2010 Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons, New York, May 6, 2010); “Nuclear Disarmament and Reduction of the Danger of Nuclear War: Working Paper Submitted by China” (presented at the Preparatory Committee for the 2015 Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons, Vienna, April 27, 2012).

17 Lu Yin, “Establishing New China-US Strategic Stability: Opportunities and Challenges,” Program on Strategic Stability Evaluation, 2012.

18 Li and Nie, “Analysis on the Strategic Stability.”

19 State Council Information Office of the People’s Republic of China, China’s National Defense in 2010 (Beijing: State Council Information Office of the People’s Republic of China, 2010).

20 Bi Yiming et al., “Research on the Quantitative Model for the Nuclear Deterrence Effectiveness” [in Chinese], Journal of Xi’an University of Engineering Science and Technology 19, no. 2 (2005).

21 Li Bin, “China and Nuclear Transparency,” in Transparency in Nuclear Warheads and Materials: The Political and Technical Dimensions, ed. Nicholas Zarimpas (Oxford: Oxford University Press, 2003); Riqiang Wu, “Certainty of Uncertainty: Nuclear Strategy With Chinese Characteristics,” Journal of Strategic Studies 36, no. 4 (2013): 579–614; Avery Goldstein, Deterrence and Security in the 21st Century: China, Britain, France, and the Enduring Legacy of the Nuclear Revolution (Münster: LIT Verlag, 2000); Devin T Hagerty, The Consequences of Nuclear Proliferation: Lessons From South Asia (Cambridge, MA: MIT Press, 1998).

22 Hans M. Kristensen, Matthew McKinzie, and Theodore A. Postol, “How US Nuclear Force Modernization Is Undermining Strategic Stability: The Burst-Height Compensating Super-Fuze,” Bulletin of the Atomic Scientists, March 1, 2017; Francis J. Gavin et al., “ISSF Policy Roundtable 1–4 (2016) on U.S. Nuclear Policy,” International Security Studies Forum, December 2016.

23 Tamir Eshel, “Multi-Object Kill Vehicle (Mokv) Begins to Take Shape,” Defense Update,

24 Hans M. Kristensen and Robert S. Norris, “Chinese Nuclear Forces, 2016,” Bulletin of the Atomic Scientists 72, no. 4 (2016). The variance is a result of whether the DF-31 missile, which has a reported range of 7,000+ km is counted as an ICBM.

25 Wu Riqiang, “China’s Anxiety About US Missile Defence: A Solution,” Survival 55, no. 5 (2013).

26 Mao Zedong, Selected Military Works of Mao Zedong [in Chinese] (Beijing: People’s Liberation Army Soldiers Publishing House, 1981).

27 Wang Jisi and Xu Hui, “A Comparative Analysis of Sino-U.S. Crisis Behavior” [in Chinese], America Studies, no. 2 (2005).

28 Wu Qiong, “An Exploration of China’s Military Deterrent Thinking in the New Era” [in Chinese], Military History Research, no. 2 (2002): 14–22.

29 Yuan Zhengling, “The Thoughts and Practice of Conventional Deterrence After the Founding of PRC” [in Chinese], Military History, no. 1 (2002): 22–26.

30 Davis B. Bobrow, Steve Chan, and John A. Kringen, Understanding Foreign Policy Decisions: The Chinese Case (New York: The Free Press, 1979).

31 Yu Yi, “Sino-Soviet Nuclear Crisis Caused by Zhenbao Island” [in Chinese], Friends of Party Members and Cadres, no. 12 (2009); Chen Hao, “Zhou Enlai Before and After the Zhen Bao Islands Clashes” [in Chinese], Extensive Collection of the Party History, no. 1 (2010); William Burr, “Sino-American Relations, 1969: The Sino-Soviet Border War and Steps Towards Rapprochement,” Cold War History 1, no. 3 (2001).

32 Zhang Tuosheng, “Zhang Tuosheng Discusses the Establishment of the State Security Committee” [in Chinese], National Culture History, no. 24 (2013).

33 Michael Glosny and Christopher Twomey, “U.S.-China Strategic Dialogue, Phase V, 2010,” Naval Postgraduate School, October 22, 2010,

34 Christopher Twomey and Kali Shelor, “U.S.-China Strategic Dialogue, Phase II Conference Report,” Naval Postgraduate School, April 12, 2007,

35 Ibid.; Michael Glosny, Christopher Twomey, and Ryan Jacobs, “U.S.-China Strategic Dialogue, Phase VII Report,” U.S. Naval Postgraduate School Center on Contemporary Conflict and Defense Threat Reduction Agency, May 2013,; Ralph Cossa, Brad Glosserman, and David Santoro, “Progress Continues, but Disagreements Remain: The Seventh China-US Strategic Dialogue on Strategic Nuclear Dynamics & the Inaugural China-US Dialogue on Space Security,” in Issues & Insights 13, no. 6 (January 2013).

36 Eben Lindsey, Michael Glosny, and Christopher Twomey, “U.S.-China Strategic Dialogue, Phase VI Report,” Naval Postgraduate School Center on Contemporary Conflict and Defense Threat Reduction Agency, April 12, 2007,

37 Cossa, Glosserman, and Santoro, “Progress Continues.”

38 Christopher Twomey and Kali Shelor, “U.S.-China Strategic Dialogue, Phase III: ‘The Role of National Perceptions of Security Environments in Shaping Sino-American Nuclear Affairs,’” (report on conference findings, organized by U.S. Naval Postgraduate School and Pacific Forum CSIS, November 4–6, 2007).

39 Cossa, Glosserman, and Santoro, “Progress Continues.”

40  Li, “Identifying China’s Nuclear Strategy”; Yi Liu, “After MAD: Deliberating China’s Nuclear Strategy and Missile Defense” [in Chinese], World Atlas, no. 3 (2010); Li and Xiao, “Rethinking the Role of Nuclear Weapons”; Hou Rui, “Research on U.S. Strategic Nuclear Missiles and the Cold War: 1945–1968” [in Chinese] (PhD disseration, Northeast Normal University, 2007).

41 Wang and Xu, “Sino-U.S. Crisis Behavior.”

42 Thomas J. Christensen, “The Meaning of the Nuclear Evolution: China’s Strategic Modernization and US-China Security Relations,” Journal of Strategic Studies 35, no. 4 (2012): 447–87.

43 Wu Riqiang, “Issues in Sino-US Nuclear Relations: Survivability, Coercion and Escalation,” UK Foreign and Commonwealth Office, 2013.

44 Christensen, “Nuclear Evolution”; Wu, “Issues in Sino-US Nuclear Relations.”

45 National Research Council, English-Chinese, Chinese-English Nuclear Security Glossary (Washington, DC: National Academies Press, 2008).

46 Barbara Opall-Rome, “U.S. Wants a Space Debris Hotline With China Patterned on the One With Russia,” SpaceNews, February 13, 2012,

47 Parts of this argument are drawn from Tong Zhao, “Strategic Stability of China-ROK-Japan Triangle,” Carnegie Endowment for International Peace, April 20, 2016,

48 Takase Kazuo et al., “Successful Demonstration for Upper Stage Controlled Re-Entry Experiment by H-IIB Launch Vehicle,” Mitsubishi Heavy Industries Technical Review 48, no. 4 (2011): 11–16.

49 “Japan’s Pro-Bomb Voices Rise as Nuke Power Debated,” Associated Press, July 31, 2012, As cited in Tong Zhao, “Strategic Stability of China-ROK-Japan Triangle.”

50 James Van de Velde, “Go Ahead. Let Japan and South Korea Go Nuclear.,” National Interest, October 1, 2016,; Anders Corr, “Japan: Go Nuclear Now,” Forbes, January 31, 2017,

51 Keir A. Lieber and Daryl G. Press, “U.S. Nuclear Primacy and the Future of the Chinese Deterrent,” China Security 3 no. 5 (2007): 66–89; “The End of MAD? The Nuclear Dimension of U.S. Primacy,” International Security 30, no. 4 (2006): 7–44.

52 Wu, “Certainty of Uncertainty.”

53 Tong Zhao, “Strategic Stability of China-ROK-Japan Triangle.”

54 “Is Missile Defense Useful?” Japan Times, May 13, 2013,

55 Brad Roberts, “Extended Deterrence and Strategic Stability in Northeast Asia,” NIDS Visiting Scholar Paper Series 1 (2013): 29–30.

56 Ibid.

57 Shou Xiaosong, The Science of Military Strategy [in Chinese] (Beijing: Military Science Press, 2013).

58 Desmond Ball and Richard Tanter, The Tools of Owatatsumi: Japan’s Ocean Surveillance and Coastal Defence Capabilities (Canberra, Australia: Australian National University Press, 2015); Lyle Goldstein and Shannon Knight, “Wired for Sound in the ‘Near Seas,’” Proceedings 140, no. 4 (April, 2014); Owen R. Cote Jr., “Assessing the Undersea Balance Between the U.S. and China,” SSP working paper, Massachusetts Institute of Technology, February, 2011.

59 Zhang Tao, “Expert: China Should Monitor Japan’s Aircraft That May Fly Over South China Sea,” China Military Online, January 13, 2016.

60 Tong Zhao, “Strategic Stability of China-ROK-Japan Triangle.”

61 Matthew Kroenig, “Nuclear Superiority or the Balance of Resolve? Explaining Nuclear Crisis Outcomes,” International Organization 67 (2009); Gavin et al., “ISSF Policy Roundtable.”

62 Takahashi Sugio, “Rebuilding Deterrence: Post-2015 Defense Guidelines Challenges Facing the U.S.-Japan Alliance,” Project 2049 Institute, May 2015.

63 Tong Zhao, “Strategic Stability of China-ROK-Japan Triangle.”

64 Roberts, “Extended Deterrence and Strategic Stability in Northeast Asia.”

65 Gavin et al., “ISSF Policy Roundtable.”

66 “Abe Tells U.S. of Japan’s Concerns Over ‘No First Use’ Nuke Policy Being Mulled by Obama,” Japan Times,

67 Eric Heginbotham et al., The U.S.-China Military Scorecard: Forces, Geography, and the Evolving Balance of Power 1996-2017 (Santa Monica, CA: RAND Corporation, 2015).

68 Clark Murdock et al., Project Atom: A Competitive Strategies Approach to Defining U.S. Nuclear Strategy and Posture for 2025–2050 (Washington, DC: Center for Strategic and International Studies, May 2015).

69 Gavin et al., “ISSF Policy Roundtable.”

70 Harvey M. Sapolsky and Christine M. Leah, “Let Asia Go Nuclear,” National Interest, April 14, 2014.