全球智库信息集成服务系统

Table of Contents

U.S.-China strategic nuclear relations are becoming more salient to U.S. defense planning and alliance management, as military tension and mutual suspicion rise in Northeast Asia. The North Korean nuclear catalyst and the need to balance allied interests make this expanding nuclear dimension increasingly complex.  

To improve mutual understanding of strategic stability and introduce the alliance element, Carnegie facilitated discussions between American, Chinese, and Japanese security experts. They focused on: a shared concept and definition of strategic stability; its purpose; and its establishment. While participants agreed on certain traditional characteristics of strategic stability, divergent views about the sources and possible remedies for currently fragile crisis and arms race stability will be difficult to bridge and do not bode well for the region, absent appropriate leadership attention.

The workshop highlighted four interconnected areas that will frustrate attempts to reduce the role of nuclear weapons in U.S.-China relations or U.S.-alliance concerns: the extent of linkage between regional/conventional conflict and the nuclear realm; Japan’s role; perceptions of mutual vulnerability; and North Korea’s role. Follow-on dialogue is recommended.

Findings and Recommendations

• The participants generally agreed that the United States is vulnerable to Chinese nuclear retaliation, but they disagreed over how Washington should respond, and the U.S.-Japan alliance is a driving factor behind this. Should the United States recognize this dynamic—thereby accepting it—or actively seek to limit such vulnerability?  
• Japanese experts are concerned that the regional conventional military balance increasingly favors China. They further worry that U.S.-China strategic stability could lead to instability at the conventional level in Northeast Asia. These concerns might be ameliorated if China and Japan could explore confidence building measures and crisis management tools in the conventional military domain.
• North Korea’s nuclear and missile programs are the most immediate and severe threat because allied countermeasures could stimulate a further Chinese response. Future U.S.-China-Japan dialogue might address North Korea–related issues of crisis management, missile defense, or military posture and exercises, implying that resolution of North Korean nuclear issues could result in a rollback of some allied and Chinese countermeasures.
• Restraint in general is underappreciated, because self-restraint or mutual restraint is difficult to measure and evaluate. If one country is taking a deterrence step it considers the least aggressive option available, it is still changing the status quo and will likely be viewed as an escalation. Mutual transparency for internal decisionmaking could help, facilitated by peacetime and crisis communication between the United States, China, and Japan.
• Future dialogues should continue to address some traditional topics, for example, offense-defense balance, tactical weapons, and strategic warning. Additionally, the emerging areas of cyber and space vis-à-vis nuclear issues, accurate signaling, and proportionality of responses are particularly fertile ground for discussion and collaborative research.

Questions Regarding U.S.-China Strategic Stability

The salience of U.S.-China strategic nuclear relations is rising, commensurate with the growth of China’s economy and military capabilities, as Beijing implements a more assertive foreign and security policy in its near abroad.¹ For the United States and its allies in the region, these developments are sowing doubt about China’s long-term intentions, while China is frustrated by Washington’s suspicion and apparent desire to maintain regional primacy. This expanding nuclear dimension can impact not only the broader U.S.-China bilateral relationship but also the multilateral geopolitics of East Asia including U.S. alliances.

The 2010 “Nuclear Posture Review Report” issued by the U.S. Department of Defense stated an explicit policy of promoting “strategic stability” with China, although the report did not define the concept and regional strategic experts have different ideas about what it means and how to foster it—severely reducing its utility as a basis for confidence building. The Carnegie Endowment for International Peace has regularly fostered intellectual exchange regarding U.S.-China strategic nuclear relations, most recently with a focus on the role of Japan.²

American and Chinese scholars and analysts have written widely about U.S.-China strategic stability in recent years, especially in the context of China’s expanding nuclear arsenal and U.S. efforts to deploy ballistic missile defense and develop various high-precision conventional weapons.³ However, far less attention has been paid to the role that Japan plays in this equation, by virtue of its alliance with the United States, its territorial disputes with China, and its own internal debates about self-defense policy and military posture. Yet bringing Japan into the lens of strategic stability highlights the convergent and divergent incentives these states have and the challenges they face to develop and sustain strategic stability.

One important concern shared by analysts in both Japan and the United States, for example, is that the existence of strategic stability between China and the United States may encourage China to be more aggressive in its relations with Japan, in particular with conventional military force. The concern about emboldened Chinese military behavior toward Japan is one of the most important outstanding issues related to U.S.-China strategic stability. This issue has been raised at various bilateral forums, including Chinese-American discussions organized under a separate Carnegie project, but it has not been systematically discussed in the context of any trilateral American-Chinese-Japanese dialogue.⁴ As U.S. President Donald Trump’s administration prepares a new Nuclear Posture Review for release in 2018, it is therefore an opportune time to clarify competing views of strategic stability and to incorporate Japanese perspectives in the discussion.

In order to promote improved mutual understanding of the meaning of strategic stability, Carnegie facilitated discussions between American, Chinese, and Japanese security experts on relevant issues. Specifically, trilateral discussion focused on three dimensions of strategic stability between China and the United States: a shared concept and definition of strategic stability; the purpose served by strategic stability; and approaches to creating strategic stability. Experts addressed the following questions:

1. What is the concept of strategic stability? Does the concept include only the suppression of incentives for using nuclear weapons and/or expanding nuclear arsenals? What does it imply for understanding the notion of unacceptable damage? Or should it also include other elements, such as the creation of political and conventional military stability? How do nuclear-related developments in India, North Korea, and Russia impact our concepts of U.S.-China strategic stability?
2. What purpose will be served by promoting strategic stability between China and the United States? Is the goal of strategic stability only to avoid nuclear escalation and a nuclear arms race (the more narrowly defined, traditional goal of strategic stability)? Or is U.S.-China strategic stability envisioned as serving some more ambitious purpose, such as paving the way for multilateral nuclear disarmament? How might strategic stability affect U.S. extended deterrence commitments to Japan? What are the implications for China-Japan security relations?
3. What are useful approaches to develop strategic stability? The primary traditional approach is to adjust the strategic force structures of the two countries in order to reduce the incentives for a nuclear first strike by negotiating arms control agreements. Is this still the most viable approach? What other approaches should be considered (such as increasing transparency and negotiating confidence building measures)? What specific role could Japan play in these approaches? What challenges might it pose?

Carnegie commissioned background papers explaining national perspectives of the United States, China, and Japan from Ambassador Linton F. Brooks, Tong Zhao of the Carnegie–Tsinghua Center for Global Policy, and Takahashi Sugio of Japan’s National Institute for Defense Studies, respectively. These papers were circulated among invited American, Chinese, and Japanese experts to foster a basis for further discussion at a trilateral workshop convened in Washington in late May 2017. The unique two-day workshop also included three bilateral discussions in order to promote as frank and comprehensive exchange of views as possible.

Multiple Views of U.S.-China Strategic Stability

Reflecting on his own country’s thinking about strategic stability—both as a general concept and as applied to relations with China—one American workshop participant said, “It is in flux.” Although the U.S. policy community reached a broad consensus on strategic stability during the Cold War in the context of bilateral relations with the Soviet Union, today’s multipolar security environment and multidomain/multitheater conflict dimensions have opened up room for diverse and even conflicting opinions regarding the changing nature of strategic stability, how to maintain it, and, in some cases, even its desirability.

The situation becomes more muddled when Chinese scholars and officials are included in the conversation, given their different perspectives and displeasure at being thought of in a similar way as the United States’ former Cold War adversary, the Soviet Union. Adding Japan further complicates the picture, since efforts by Washington to reassure Tokyo and Beijing on the nuclear front are often mutually exclusive. Although this project revealed some positive aspects of trilateral views on U.S.-China strategic stability, overall it underscored the persistence—and, in some ways, the darkening and lengthening—of the nuclear shadow over Asia. The only silver lining, perhaps, is that the current lack of clarity in policy thinking about strategic stability provides, at least, an opportunity to contribute to new consensus building and ideally a more peaceful future.

The background papers are included in this report’s appendices, and there is no need to summarize here their concise and well-crafted arguments. They deserve to be read as their authors intended. Instead, the following section highlights key areas of agreement and misalignment found in the background papers, folding in the main debates and observations made during the two-day trilateral workshop. The final section considers the policy implications of our collective views of U.S.-China strategic stability and recommends certain issues for further bilateral and trilateral discussion.

A Useful Foundation for Dialogue on Strategic Stability

On the positive side, the benefit of several years of various bilateral Track II dialogues involving these three countries was evident from some constructive debates that shared many common points of reference and terminology. Participants agreed on the relevance of certain traditional characteristics of the strategic stability concept, including the premise that it only applies to countries with a plausible path to potential conflict (for example, strategic stability is meaningless in a U.S.-UK or UK-France context). Moreover, for the United States and China, a path to conflict is not unthinkable but it is not particularly likely at the moment. This is especially true in the nuclear realm, and for one critical component of strategic stability—specifically “first strike stability,” when in a crisis or conventional military conflict there is no incentive to be the first to use nuclear weapons—there was general agreement that this is not an area of immediate concern.

In addition, although the United States and China tend to define strategic stability differently, the project showed basic agreement on two other key aspects within the traditional U.S. framework for strategic stability left over from the Cold War. These are “crisis stability” (where no country has incentive to be the first to use military force of any kind) and “arms race stability” (when neither side believes it can improve its relative position by building more nuclear weapons). Chinese scholars do tend to see strategic stability with the United States in broader terms, given the asymmetry in their nuclear strength and posture, and they consider general political-military relations—including economic and diplomatic considerations—as important factors. But, overall, the workshop discussion unfolded from a starting point of mutual understanding about the parameters of the topic and the project’s ultimate objective. As one Chinese scholar noted, “The goal is the same for everyone: that we want to avoid a nuclear arms race and any nuclear use.”

Conflicting Perspectives and Lack of Trust Undermine Stability

However, divergent views about the sources and possible remedies for currently fragile crisis and arms race stability will be difficult to bridge and do not bode well for the region, absent appropriate leadership attention. The workshop highlighted at least four interconnected areas of disagreement or misalignment that will frustrate attempts to reduce the role of nuclear weapons in U.S.-China relations or U.S.-alliance concerns. These are: 1) the extent of linkage between regional/conventional conflict and the nuclear realm; 2) the role of Japan; 3) perceptions of mutual vulnerability; and 4) the role of North Korea.

Conventional-Nuclear, Regional-Intercontinental Linkage

Viewed from Washington, the potential path to a U.S.-China nuclear exchange starts with conventional conflict in the Asia-Pacific region, possibly involving Taiwan or a skirmish on or above the ocean surrounding disputed territory. The Cuban Missile Crisis during the Cold War and the potential for clashes with North Korea today have conditioned U.S. policymakers to consider nuclear escalation risks from seemingly minor regional incidents. This tendency is reinforced by recent Russian moves, wherein “Russia has set out military doctrine for three levels of war: strategic, regional, and local,” as one U.S. participant described, “and all deterrence tools [including special forces, covert operations, space, cyber, nuclear, and so on] apply to all three theaters.” Many American specialists believe that competition for conventional military influence in Asia will stimulate the same key question: What does strategic stability mean at the regional level of war, not just at the strategic level between two nuclear powers?

In contrast, Chinese authorities traditionally draw a clear line between China’s nuclear arsenal and the rest of its military when considering deterrence and potential conflict or escalation issues. It is only in recent years that Chinese specialists have started engaging their American counterparts in discussions about cross-domain escalation, and even then they emphasize the so-called nuclear taboo, which presupposes the non-use of nuclear weapons as a prohibitive norm.⁵ In this sense, nuclear weapons are not intended to be used and exist only to deter a nuclear attack. One Chinese participant claimed that “China doesn’t see [nuclear use] as regional theater versus strategic level issue, because if China used them regionally [in East Asia] it would be against a non-nuclear weapon state, which goes against its no-first-use policy and would have huge ramifications.” The Chinese view, therefore, suggests that nuclear weapons should be a non-factor with regard to U.S. allies in East Asia.

However, Chinese objections to some U.S. and Japanese regional missile defense systems—including U.S. deployment of a Terminal High Altitude Area Defense (THAAD) system in South Korea—create suspicions in Japan and the United States about the strategic role for Chinese short- and intermediate-range nuclear forces. The allies wonder whether or not Beijing views this as an important regional retaliatory capability in which it will continue to invest. Clearly, this is an area that would benefit from deeper discussion among American, Japanese, and Chinese specialists, in part because it is so intertwined with other areas of disagreement.

The Role of Japan

U.S. scholars tend to see Japan’s defense capability and the U.S.-Japan alliance as contributing to crisis stability because it discourages Chinese attempts to use military means to resolve territorial or sovereignty disputes in the East China Sea. They also believe that high-level U.S. reassurances that the Senkaku/Diaoyu Islands are covered by the U.S.-Japan Security Treaty help the situation, because it is clear that any attempt by China to seize the islands would be met with combined U.S. and Japanese military power. U.S. and Japanese scholars cautioned that China’s excessive maritime claims and aggressive enforcement actions—including the use of paramilitary forces and civilian fishing fleets—represented a form of escalation that endangers regional crisis stability by bringing the parties just one small step away from military conflict on a regular basis.

Chinese participants, however, expressed concern about the U.S.-Japan alliance as an enabler of U.S. first-strike capability and about Japan’s own rising militarism. They highlighted Japan’s so-called southwestern wall in the Ryukyu Island chain and U.S.-Japanese cooperation in antisubmarine warfare, which could inhibit China’s second-strike ability. Viewed from Beijing, the allies seem to exaggerate threats from North Korea and China’s military to serve political ends or to justify investments in continued military preeminence. The allies’ active contestation of Chinese core interests sours political-military relations between them and has a negative impact on China’s perception of strategic stability, since Beijing views these two aspects as closely linked under its broad definition for the latter. Some Chinese participants also expressed concern that Japan’s missile defense investments, and joint development of missile defenses with the United States, could degrade China’s nuclear second-strike ability to the point where it emboldens the United States to consider striking first with nuclear weapons.

Considering the role of Japan and the regional-nuclear connection led to multiple workshop discussions about mutual vulnerability in the U.S.-China nuclear relationship. Key points of debate included the extent to which mutual vulnerability is an accurate description in the U.S.-China nuclear balance, whether Washington accepts this as a reality and maybe even a contribution to stability,⁶ the difference between mutual vulnerability and mutual deterrence,⁷ and the impacts on mutual vulnerability by nuclear modernization, new prompt-strike conventional weapons, or cyber- and space-based capabilities. A few Japanese participants felt strongly that while some degree of U.S.-China mutual vulnerability might be unavoidable, if it rose to a level of thoroughly deterring U.S. nuclear use at the regional level, then this could be dangerous for Japan in ways explained by the stability-instability paradox.⁸

In Tokyo’s opinion, the Asia-Pacific region suffers from an asymmetry of vulnerability. China and North Korea have acquired an invulnerable regional strike posture with road-mobile missiles, while Japan and South Korea lack any means to put them at risk. In China’s case, this is combined with an increasingly large, sophisticated, and expeditionary conventional military capability. Beijing has expressed no interest in leveraging such theater dominance for tactical advantage, but some Japanese experts have argued that this military strength—together with China’s economic influence—is an integral part of its coercion tactics in the region. Forward deployed U.S. forces and U.S. strategic strike capabilities counterbalance much of China’s (and, to a lesser extent, North Korea’s) regional advantage, but this would tip back in China’s favor if U.S. nuclear forces are deterred out of the equation.

Mutual Vulnerability

Some American and Japanese participants highlighted the “potential desirability of instability,” because the risk of escalation to the nuclear level can help improve deterrence at all levels (that is, all sides would worry about escalation), but there was no consensus on this point among the allies, and the Chinese disagreed with the premise. On the one hand, Washington has an incentive to take seriously China’s nuclear arsenal and even accept a degree of mutual vulnerability, since it could foster restraint and help Beijing remain content with its current deterrent force and posture and refrain from more investments. On the other, Japan worries that too much U.S. deference to China could lead to greater low-level conventional conflict in the region, which not only threatens Japan’s interests but is also precisely what Washington and Tokyo fear could lead to nuclear war.

U.S. ambivalence toward (and Japan’s disdain for) U.S.-China mutual vulnerability has Chinese specialists worried that the United States will look continuously for ways to expand its nuclear advantage vis-à-vis China through the use of missile defenses and new technologies that improve counterforce targeting and lower the threshold for nuclear use.⁹ Chinese participants in the workshop warned of arms race instability as a result. Some also wondered if mutual vulnerability could be a sufficient foundation for strategic stability, given the trilemma for Washington of appealing simultaneously to Beijing and Tokyo while protecting its own national security. It is partly because of this lack of faith in mutual vulnerability that China seeks to supplement strategic stability with other concepts such as “new type of major power relations” and U.S.-China interdependence, “consensus and communication,” and the nuclear taboo. While the American and Japanese participants acknowledged some potential value of these factors, they saw them as susceptible to failure when core interests conflict.¹⁰

Participants also discussed the complicating factors of cyberspace and other domains, as they relate to mutual vulnerability and strategic stability. One view of these issues, articulated by the American scholars David Gompert and Phil Saunders, is that defense innovation was, in some ways, making these issues so complex that their solutions were actually becoming simpler.¹¹ The confluence of outer space, cyberspace, air and seaborne autonomous systems (and some other realms) suggests that integrated attacks could become too complex to defend in the future, which means that mutual vulnerability could exist across all domains. In theory, because leading nations like the United States and China will always “choose to compete” in new domains—as one American noted—this exposure to rivals and such comprehensive vulnerability could become a major disincentive for conflict, which, in turn, should underpin stability. Workshop participants, however, did not give much confidence to this theoretical conclusion.

The Role of North Korea

Whatever efforts the United States, China, and Japan can make to address the mutual vulnerability conundrum, North Korea remains a likely spoiler, and this issue occupied a significant portion of workshop debate. Part of the problem is a lack of confidence that North Korean leadership shares the widely accepted norm of the nuclear taboo, which will drive the United States and Japan (and South Korea) to take increasingly dramatic passive and active defensive measures as North Korea builds its nuclear arsenal. These include several steps—such as missile defenses, new surveillance and reconnaissance deployments, new strike deployments, and use of cyber weapons—that are already causing many Chinese specialists to doubt the adequacy of their second-strike capability. It might eventually include preemptive strikes against certain North Korea targets and/or a more operationally robust nuclear retaliation posture vis-à-vis North Korea to convince North Korean leader Kim Jong-un that any nuclear use by him will mean his country’s quick annihilation.

Steps such as these will inevitably undermine U.S.-China arms control stability by stimulating countermeasures by Beijing, even if Chinese leaders understand that the underlying reasons for the allies’ proactive steps are mostly related to North Korea. China could expand its nuclear stockpile and long-range missile force, modernize existing missiles by adding new features designed to foil missile defenses, and invest in cyber and/or space-based weapons to counter a perceived U.S. advantage. U.S. and Japanese workshop participants did discuss the possibility of modifying or scaling back certain types of defense deployments vis-à-vis North Korea, if this might alleviate some specific Chinese concerns and avoid a nuclear arms race, but the general conclusion was that such restraint was unlikely to be appreciated by China. In fact, Chinese participants complained that Beijing has already exercised restraint on various occasions (in the nuclear realm, with North Korea, and in the South and East China Seas), but such accommodation is rarely recognized by the United States and Japan. Such is the nature of restraint, which is usually underappreciated by an opponent and overvalued by oneself, but it is at least an area that lends itself to improvement through regular dialogue and modest trust-building measures.

Findings and Recommendations

The project’s trilateral discussions for the first time allowed and encouraged experts from the United States, China, and Japan to directly exchange opinions on the special roles and concerns of Japan with regard to U.S.-China strategic stability. Although the participants were not able to reconcile all of their views on these issues, the workshop did yield some useful findings that would add considerable value for future dialogue.

An overarching takeaway from the project is the need and potential value of more consistent dialogue on U.S.-China strategic stability involving specialists (and policymakers, if possible) from all three countries. As noted above, the current lack of clarity in policy thinking about this topic provides an opportunity to contribute to new consensus building within these relatively small intellectual communities. More frequent dialogue might also help to reduce the high level of mutual distrust that permeates these diplomatic and security issues. There are several different aspects of strategic stability that should be discussed, and these can be addressed in complementary bilateral (that is, U.S.-China, Japan-China, and U.S.-Japan) and trilateral dialogues.

Two key issues discussed in the project include (1) whether or not China has a strategically significant nuclear retaliatory capability vis-à-vis the United States and (2) whether the United States should recognize this dynamic—thereby accepting it—or actively seek to limit such vulnerability. The former is a scientific judgment with a degree of uncertainty while the latter is a strategic choice. The participants generally agreed that the United States is vulnerable to Chinese nuclear retaliation, but they disagreed over how Washington should choose to respond, and the U.S.-Japan alliance is a driving factor behind this dynamic. This finding supports the importance of the project and highlights the need for more attention on the role of Japan in the issue of U.S.-China strategic stability.

A major Japanese concern about U.S.-China strategic stability comes from Tokyo’s view that the regional conventional military backdrop is tilting out of balance to increasingly favor China. Japanese experts worry that U.S.-China strategic stability could lead to instability at the conventional level in Northeast Asia. If China and Japan could explore confidence building measures and crisis management tools in the conventional military domain, it could mitigate their security dilemma and might ameliorate Japanese resistance to U.S.-China strategic stability.

Future trilateral dialogues would also benefit from diverse teams of experts, including those with conventional military expertise. This can bring forward issues related to the nuclear-conventional nexus and the linkage to regional-intercontinental dimensions of strategic stability and escalation.

The topic of restraint in general is also underappreciated in these types of dialogues, in the sense that self-restraint or mutual restraint is difficult to measure and evaluate. Even if one country is taking a deterrence step that it considers the least aggressive option available, it is still changing the status quo and will likely be viewed by the other as an escalation of sorts. In this sense, some level of mutual transparency for internal decisionmaking could be useful, and this links to the broader issue of peacetime and crisis communication between the United States and China (and involving Japan). Greater intellectual exchange in bilateral and trilateral formats is required at both the Track I and Tra