The Impact on Strategic Stability: A Gap Between Self-Perceptions and Reality

Table of Contents

Although Chinese experts and analysts have long viewed their SSBNs as motivated by defensive considerations and, therefore, beneficial for strategic stability, there are operational and developmental aspects to Beijing’s SSBN program that reveal a more complex reality.

China’s Self-Perceived Contribution to Strategic Stability

For several decades, China possessed only a rudimentary nuclear weapons capability with limited survivability. Even today, the guaranteed viability of Beijing’s arsenal is still a point of debate. Some Western scholars have recently argued that the United States may be able to preemptively destroy all of China’s nuclear forces in a disarming first strike.¹ Some Chinese strategists share this opinion and fear that China’s small arsenal of intercontinental ballistic missiles (ICBMs) does not provide a guaranteed second-strike capability.²

In response to this concern about its nuclear arsenal’s perceived vulnerability, some senior Chinese military officials have traditionally argued that a sea-based nuclear capability would prove more survivable than land-based systems. Admiral Liu Huaqing once estimated that “fewer than 10 percent of China’s land-based missiles would survive a large-scale nuclear first strike; the less vulnerable [submarine-launched ballistic missiles] SLBMs would preserve our nuclear counterattack capabilities.”³ Hailed as the father of the modern Chinese navy, Liu served from 1989 to 1998 as vice chairman of the Central Military Commission, China’s top national security decisionmaking body. This assessment has not changed. As recently as 2011, other Chinese naval experts similarly concluded that only 5–10 percent of the country’s land-based and airborne nuclear weapons would survive a nuclear first strike, whereas the projected survival rate of sea-based nuclear weapons could be as high as 90 percent.⁴

With that in mind, the goal of China’s SSBN fleet—sometimes called the Second Nuclear Force—is to dispel any doubts potential adversaries may have about Beijing’s retaliatory capability and to force Washington to recognize unequivocally that China and the United States have a nuclear relationship based on mutual vulnerability.⁵ In assuming that the two countries are mutually vulnerable, Chinese experts expect that their SSBNs will greatly enhance strategic stability by deterring potential rivals from attempting a nuclear first strike or nuclear coercion in a crisis, and by dissuading any rivals from even attempting to obtain first-strike capabilities against China.

Although there are some reasons to wonder if Chinese concerns about the survivability of land-based nuclear weapons (versus sea-based ones) may be overstated, the fact remains that these concerns are widely shared among Chinese policymakers and inform policy accordingly. Admittedly, China has made impressive progress, in recent decades, on modernizing its land-based road-mobile nuclear missiles by improving their accuracy, mobility, and responsiveness. Moreover, Chinese naval experts have a parochial interest in promoting naval weapon systems. That being said, general concerns persist across the board among Chinese experts about the survivability of land-based systems, in some cases more acutely than before. In particular, experts worry that growing U.S. missile defense, conventional precision strike, and space-based surveillance capabilities could collectively facilitate sophisticated preemptive attacks that could pose a significant threat to China’s land-based nuclear forces.⁶

Chinese strategists’ perception that SLBMs are less vulnerable than other nuclear delivery systems proceeds from several understandings about SSBNs. First, SSBNs are highly mobile and can considerably “expand the combat area” by patrolling in open oceans and thus “increase the [geographical element of] surprise” of an attack.⁷ Second, SSBNs can be extremely stealthy. Detecting and tracking enemy SSBNs requires a tremendous amount of military resources. Consequently, preemptively destroying SSBNs is “more difficult than destroying land-mobile launch system[s].”⁸

Sea-based nuclear weapons offer other advantages as well. Because SSBNs can launch missiles from close to an enemy’s territory and thus reduce the time for the enemy to employ defensive measures, SLBMs have a better chance than ICBMs do of thwarting enemy missile defense capabilities.⁹ Moreover, if located in the South Pacific, Chinese SSBNs would be able to launch missiles along trajectories not currently covered by U.S. missile defense radars.¹⁰ In fact, the 2013 edition of the Science of Military Strategy—an important military textbook written by prominent Chinese military scholars and published by the People’s Liberation Army’s (PLA) Academy of Military Sciences—makes an explicit connection between U.S. missile defenses and China’s SSBN program:

Faced with the objective situation of the United States and countries on China’s periphery actively developing missile defenses, developing China’s sea-based deterrent force is significant for the reliability, credibility, and effectiveness of protecting China’s nuclear deterrent and counterstrike capabilities.¹¹

Foreign experts also have hypothesized that China could have other potential tactical motivations for acquiring SSBNs. Some U.S. experts, for example, have speculated that China could use its SSBN fleet to force the United States to divert ASW resources away from other important tasks. These experts suggest that, during a military crisis between the two countries, China could visibly mobilize its SSBNs to explicitly threaten the U.S. mainland and other core U.S. interests. According to this thinking, the goal would be to force the United States to devote more of its ASW resources—especially its nuclear-powered attack submarines (SSNs)—to finding and tracking Chinese SSBNs. This would leave U.S. aircraft carriers and other important surface ships without adequate protection from Chinese attack submarines.¹² While this strategy sounds possible in theory, it has not been seriously discussed in Chinese policy discourse; there is no evidence that China has embraced the idea of risking its SSBNs—a core strategic asset—for tactical military gains.

Another argument in relevant foreign literature is that Chinese SSBNs are intended to hold Indian targets at risk as part of Beijing’s efforts to exercise deterrence vis-à-vis New Delhi.¹³ Scholars who advance this theory point out that, if deployed in the South China Sea, Chinese SSBNs could easily launch strikes against India without sailing into the Indian Ocean.¹⁴ Relevant Chinese literature, however, only rarely expresses an interest in using SSBNs for deterrence against India.

Admittedly, if China were intent on threatening Indian targets using its SSBNs, it would not need to declare this goal openly. Yet there have been no indications, even in Chinese publications not intended for foreign consumption, that the possible deployment of SSBNs in the South China Sea is, even in part, driven by enhancing deterrence against India. That said, over the long term, Chinese strategists are watching Indian efforts to continue closing the gap between the two countries’ nuclear capabilities by extending the range and number of Indian strategic missiles and building its own SSBNs.¹⁵ If this trend continues, it is not entirely impossible that China may want its SSBNs to play a role in deterring India.

China views its SSBN capability not as a tactical military asset but as a strategic capability that is increasingly important for maintaining a credible second-strike capability.

Despite these foreign theories, China views its SSBN capability not as a tactical military asset but as a strategic capability that is increasingly important for maintaining a credible second-strike capability against potential nuclear rival(s) and that, therefore, contributes to strategic stability. In reality, however, a systematic analysis of key operational and developmental aspects of China’s SSBN program shows that the overall impact on strategic stability of this program and of the likely countermeasures other countries might take in response is much broader and more complex.

Chinese SSBN Operations and Crisis Stability

There are at least three key operational issues pertaining to China’s SSBNs that have important implications for crisis stability: the submarines’ alert status, the pre-delegation of launch authority, and the merits of continuous-at-sea deterrence.

Alert Status: One of the main concerns foreign observers have is that China may arm its SSBNs with nuclear warheads during patrols, as other nuclear powers do. To complicate matters, the term “alert” has different meanings in the naval jargons of different countries. In the United States, for instance, alert is a narrow, technical term that refers to precise operational requirements: an alert SSBN is submerged, undetected, able to receive communications, in range of targets, and has readied its weapons systems to respond on short notice.¹⁶ In U.S. terminology, an alert SSBN is at the highest possible level of readiness.

By contrast, in Chinese official documents, such as defense white papers, the word “alert” is most commonly used in the terms “alert level” or “alert status” to describe general efforts to increase the readiness of the country’s nuclear forces. In Chinese terminology, nuclear forces that have been alerted are not necessarily at the highest level of combat readiness. This report uses the term in the second relative sense.

Existing open-source information about the alert status of Chinese nuclear weapons is mostly about the country’s land-based missiles. Currently, China is believed to maintain a low alert level for its land-based nuclear missiles during peacetime, with missiles and warheads stored separately.¹⁷ Beijing’s 2013 defense white paper, for example, indicates that China keeps the readiness of its nuclear forces at a “moderate level” and will only raise the alert level “when the country faces a nuclear threat.”¹⁸ Meanwhile, the Chinese government has promoted international efforts to reduce the alert level of other states’ nuclear weapons.¹⁹ China is proud of its posture, which enhances its image as a responsible nuclear weapon state.

[K]ey operational issues pertaining to China’s SSBNs . . . have important implications for crisis stability: the submarines’ alert status, the pre-delegation of launch authority, and the merits of continuous-at-sea deterrence.

It is standard practice for British, French, U.S., and Russian SLBMs alike to be armed with nuclear warheads when they are conducting patrols, even in peacetime. Whether China follows this practice is unclear.²⁰ If it does, Chinese SLBMs armed with nuclear warheads would represent a major departure from long-standing Chinese policy, but there would be some practical advantages to such a posture. Not least of these advantages would be the ability to sidestep during a crisis the logistical and security challenges of transporting warheads to previously unarmed SSBNs at sea or having the SSBNs sail back to port to pick up the warheads. Such activities may be detected by an enemy and risk being misinterpreted as preparations for nuclear first use. Also, loading an SSBN with missiles and warheads would take time that might not be available during a rapidly developing crisis. Furthermore, some U.S. and British experts believe that if SSBN crews are not trained frequently to operate with missiles during peacetime, they might be prone to making mistakes in a high-pressure crisis.²¹ This concern may influence the thinking of Chinese strategists as well.

Despite these considerations, however, putting Chinese sea-based nuclear weapons on relatively high alert during peacetime patrols would have implications for strategic stability. Doing so would likely create an impression among foreign observers that China could conduct a more rapid surprise nuclear attack in the future. This perception could increase an enemy’s incentive to attack Chinese SSBNs early in a serious conflict to preempt the possibility of China using nuclear weapons first. Moreover, the U.S. political scientist Scott Sagan has pointed out that in complex engineered systems like nuclear weapons, there are (almost inevitably) some risks of accidents.²² Maintaining a high alert level for SSBN forces would come at the expense of safety and security, potentially making technical or operational incidents more likely to occur and more likely to carry serious consequences.

Launch authority: A second operational issue that has implications for crisis stability is whether or not China should pre-delegate launch authority for its nuclear missiles to submarine commanders. The question stems from the reality that maintaining reliable communication channels with SSBNs at sea is difficult. If communication between a submarine and a country’s national command authority were to be jeopardized, the danger of an unauthorized SLBM launch could increase.²³

A lack of clarity exists on this point in China’s case, partially because there is a debate about which PLA branch is responsible for operating and employing the country’s sea-based nuclear weapons. A close reading of China’s 2013 defense white paper implies that the PLA Navy, not the Second Artillery Force, was responsible for Chinese SLBMs at that time.²⁴ Presently, some military commentators have suggested that the PLA Rocket Force is now responsible for all Chinese land-based, sea-based, and air-delivered nuclear weapons.²⁵ The PLA Rocket Force is a newly established service branch that replaced the Second Artillery Force in January 2016, as a result of military reforms enacted by Chinese President Xi Jinping’s administration.

There is, however, no persuasive evidence that SSBNs have become part of the Rocket Force. Irrespective of which service is responsible for China’s SSBNs, the country’s policy remains that all nuclear forces are under the direct command of the Central Military Commission. The military service branches have no authority to issue launch orders to nuclear forces during peacetime.²⁶ The challenge posed by SSBNs is that the technical difficulty of maintaining highly reliable communication channels could create incentives for the national leadership to consider pre-delegating launch authority during a crisis.

Generally speaking, there are two potential approaches to managing launch authority for SSBNs. One option is to permit the submarine to launch its missiles only after receiving an explicit order from the national command authority. In the case of the United States, only after the president has issued a launch order would the code to unlock the safe containing the launch keys be transmitted to submarine officers. Without this code, the submarine crew cannot launch the missiles.

The other option is to grant some authority to the submarine crew to launch SLBMs in extreme circumstances. Like its U.S. counterpart, the national command authority of the UK has the ability to transmit launch order to SSBNs. If, however, UK submarine officers were to become convinced—through various prescribed tests—that the UK had been destroyed in a conflict, the captain could act according to a pre-written letter from the prime minister previously locked in a safe. This arrangement leaves the crew some latitude to decide when to act on the basis of what is contained in this letter of last resort, and it makes it theoretically possible that the prime minister’s letter may give the submarine captain some flexibility about whether to launch missiles based on his or her own judgment of the situation.²⁷

For Beijing, the question of launch authority is closely tied to the reliability of the country’s communications system. China has made progress on enhancing the reliability of its means of communicating with SSBNs in recent years, despite the questions that the U.S. government and some experts have raised about the system’s sophistication.²⁸ If China continues to prioritize the modernization of this system, if Beijing feels confident in its ability to reliably communicate with SSBNs at sea in a timely manner, and if the country feels confident in its ability to protect its top leadership in a crisis, then China may be able to avoid pre-delegating launch authority to SSBN commanders. This would reduce the risk of unauthorized missile launches. An important consideration is China’s degree of concern that, in a conflict, an enemy might interfere with its SSBN communications. Such concerns could prompt China to pre-delegate some launch authority to SSBN commanders. If that were the case, enemy interference with SSBN communications could, in a conflict, increase the risk of an unauthorized launch.

Patrol strategy: A third decision with implications for crisis stability is whether or not China chooses to maintain a so-called continuous-at-sea deterrence. This posture requires a country to maintain at least one SSBN in patrol areas at all times, an approach that has been adopted by France, the UK, the United States, and Russia (although the practice lapsed in Russia for a while after the fall of the Soviet Union). The advantages and disadvantages of this approach, however, have not been systematically debated in the open-source Chinese literature.

Examining the patrol practices of other nuclear powers is instructive. The United States keeps as many SSBNs as possible on patrol.²⁹ This posture ensures that a very large number of U.S. nuclear weapons would survive even a sudden, unexpected, large-scale, nuclear first strike. However, the utility of this strategy in peacetime is highly questionable, given the extremely low chances of an out-of-the-blue first strike—without any reason or warning—apart from a deep crisis or conflict. In addition, this posture is very expensive to implement, as it requires not only a large number of SSBNs but also a highly sophisticated logistics and maintenance system to maximize the SSBNs’ availability. Moreover, the United States assigns two crews to each nuclear-armed sub. By contrast, the UK and France—each of which have a smaller force of four SSBNs—have adopted the more modest approach of keeping only one SSBN on patrol at all times. Even so, questions are frequently raised—particularly in the UK—about whether continuous-at-sea deterrence is really necessary, especially given that many British analysts argue that their country faces no existential threat.³⁰

Some Chinese military commentators assume that Beijing’s ultimate goal is continuous-at-sea deterrence. Indeed, the fact that China has built at least four 094-type SSBNs seems to confirm such speculation. However, there has not yet been any open discussion about whether Beijing should adopt this posture. China has long believed that a nuclear war between nuclear weapon states, let alone an out-of-the-blue surprise nuclear strike, is unlikely.³¹ If this belief is correct, China may be able to safely maintain the credibility of its nuclear deterrent without continuous SSBN patrols during peacetime.

That said, the downside of intermittent patrols is that submarines could be exposed to preemptive strikes—even conventional preemptive strikes—while in port. To mitigate this risk, China would need to quickly deploy its SSBNs at the first sign of a serious military crisis. If, however, an adversary were to detect these SSBN movements, it could misinterpret them as aggressive and consequently feel pressured to take the escalatory step of preempting an imminent attack. Additionally, China would need to develop effective crew training and equipment maintenance mechanisms to compensate for the lack of training opportunities intermittent patrols would offer compared with those of a continuous-at-sea deterrent.

Chinese SSBN Fleet Growth and Arms Race Stability

The effect of China’s nuclear-armed submarines on strategic stability will also be felt in terms of arms race stability. This impact will largely be a product of the future growth of China’s SSBN fleet and other complementary military assets, the growth of rival naval assets, and (most importantly) both sides’ perceptions of how these procurement decisions affect the overall military balance.

Whether or not China’s SSBNs will fuel an arms race is not determined entirely by whether Beijing’s primary intention is simply to maintain the status quo by preserving the viability of its overall nuclear deterrent. What matters is how other players interpret Chinese efforts. If they believe that China’s intentions are not benign and that the growth of Chinese nuclear capabilities may enable Beijing to behave more assertively, they might react by significantly building up their own capabilities and investing in new countermeasures. China’s deployment of SSBNs and supporting general-purpose forces may, therefore, quickly change its overall military capabilities and hence the calculations that foreign analysts make about China’s strategic intentions, potentially contributing to a new round of nuclear and conventional arms competition.

If [other countries] believe that China’s intentions are not benign . . . they might react by significantly building up their own capabilities and investing in new countermeasures.

When assessing the potential growth of China’s nuclear arsenal, it is worthwhile to establish an approximate baseline of the country’s current nuclear stock. One widely cited assessment puts China’s existing nuclear stockpile at around 206 warheads, excluding warheads on SLBMs.³² This stockpile includes only about fifty-two ICBM launchers that could potentially launch missiles against the continental United States.³³ If China succeeds in fielding between five and eight 094-class SSBNs in the near future, as some senior U.S. officials and experts seem to predict, China will add to its arsenal between sixty to ninety-six strategic missile launchers capable of striking the continental United States, as each such submarine carries twelve SLBM launchers. To be sure, it is unlikely that all Chinese SSBNs could be in their patrol areas, ready to launch missiles against the United States, at the same time.³⁴ There is no available information about whether China’s SLBM warheads would come from new stock or be diverted from possible existing reserves. This means that it is not yet possible to conclude how much China’s overall warhead stock will grow as a result of the addition of the SSBN capability.

There is little doubt that this new SLBM strike capability will affect threat perceptions in foreign countries, especially the United States. Some U.S. officials and experts are already alarmed by what they see as a rapid increase in Chinese nuclear capabilities and potential future developments.³⁵ The recently revealed ship assembly facility of the Bohai Shipbuilding Heavy Industry Company further contributes to such concerns.³⁶ This new facility is often described by Chinese military commentators as the largest of its kind in the world; it is reportedly capable of working on five to six nuclear submarines simultaneously. Cankao Xiaoxi—China’s largest newspaper by circulation, which is published by the official Xinhua News Agency—cited foreign reports stating that this “giant” facility will be used to build China’s most advanced SSBNs and SSNs on a scale unmatched by any other state.³⁷ Although questions have been raised about the accuracy of these reports,³⁸ there is a widespread perception that this facility could contribute to a quick future buildup of China’s SSBN fleet.

The United States may feel less threatened if it believes that China’s SSBN growth is motivated exclusively by the desire to secure its second-strike capabilities. However, if Washington suspects that the program is actually driven by nondefensive goals—such as rising nationalist sentiment, a desire to catch up with the other major powers, or bureaucratic interests—that Washington cannot predict or influence (or that Washington must at least hedge against this possibility), the existing security dilemma between the two major nuclear powers would be exacerbated in ways that could lead to more intensive arms competitions.

Historically, China’s decision to start an SSBN program was very much motivated by a desire to acquire capabilities similar to those of other major nuclear powers.³⁹ China’s top leadership decided to start developing a sea-based nuclear weapon capability in 1958,⁴⁰ even before the country’s first nuclear test in 1964. Moreover, at that time, China’s poorly equipped military was in dire need of even the most basic military hardware. Given the circumstances, the leadership’s decision to pursue a highly complex weapons system, like a nuclear missile submarine, suggests that it was driven by a desire to follow a trend in military development led by major world powers.

Indeed, during the 1960s and 1970s, the lack of urgency in China’s SSBN development suggests that it was not driven by a pressing military need. The Defense Science and Technology Commission only developed specific operational requirements for China’s first nuclear attack submarine in 1966, eight years after their decision to acquire the submarine. Research and development into China’s first ballistic missile submarine was similarly delayed by a lack of clear operational requirements.⁴¹ For at least three decades after the decision to start the program, Chinese nuclear submarines were a lower priority than land-based missiles and other military programs. When the country’s defense budget was particularly tight in the early 1960s, the nuclear submarine program was discontinued until 1966. Even after that, for quite a long time up until the mid-1990s, the program received only moderate political attention and financial support.⁴²

In recent decades, even as China has made the development of SSBNs a higher priority, international trends have continued to strongly influence the thinking of Chinese strategists. They take note that every other nuclear weapon state that has signed on to the Nuclear Non-Proliferation Treaty (NPT) has increased the role of sea-based nuclear weapons in its nuclear posture, and they conclude that “from the global perspective, the proportion of sea-based nuclear capability in national nuclear deterrent systems will continue to rise.”⁴³ For example, they point out that sea-based nuclear weapons already represented 60 percent of all U.S. deployed nuclear warheads by 2015. This figure is expected to have risen to 70 percent by 2018. Chinese analysts expect the equivalent figure for Russia to increase from 23 percent in 2015 to 57 percent in 2020.

Crucially, Chinese strategists see that similar developments are occurring across all “mid-level nuclear weapons states,” a group that consists of France and the UK and to which they believe China belongs. They point out that “establishing a minimum underwater nuclear capability is a common understanding among mid-level nuclear weapons states,” which further reinforces the belief that “nuclear submarines armed with strategic nuclear missiles are the most ideal type of nuclear retaliation capability.”⁴⁴ In short, Chinese analysts generally perceive SSBNs as befitting a country of China’s stature.

In other words, the urgency and necessity of China’s development of an additional sea-based nuclear capability has not yet been publicly demonstrated. To be sure, there is increasing recognition in China that SSBNs can play a critical role in strengthening its nuclear deterrent in the face of a new geostrategic environment and technological threats. In particular, many Chinese experts worry about the credibility of a nuclear second-strike capability based solely on land-based ICBMs given advances in U.S. missile defense and conventional precision strike capabilities. Nonetheless, there has been little authoritative research—that is openly available, at least—about the extent to which U.S. missile defense and conventional precision strike capabilities may undermine the effectiveness of Chinese land-based ICBMs in the foreseeable future.

Additionally, the availability of new financial and material resources has presumably played a role in the rapid growth of China’s SSBN fleet. Decades of rapid economic development have, for the first time, offered the PLA opportunities to procure military capabilities that it had only dreamed about before. China’s gradual military transformation, including a reduced emphasis on the traditionally central role of ground forces, provides an opportunity for the air force and navy to rapidly expand their missions and capabilities. Some foreign analysts suspect that the parochial interests of China’s different military services and the defense industry have started to become a more important factor in driving the country’s military investments, including nuclear modernization.⁴⁵ The rapid development of China’s SSBN fleet may reflect this growing complexity in military procurement plans.

Furthermore, there are increasingly frequent calls in some nationalistic Chinese media outlets for China not to “hesitate to strengthen strategic nuclear capabilities” and to gradually match the nuclear capabilities of the United States.⁴⁶ This development is fairly new; in the past, it was rare to hear such open advocacy for China to greatly expand its nuclear arsenal. Worryingly, such radical newspaper editorials have received overwhelming support from readers—based on reader feedback, at least. This raises the concern that a growing sense of nationalism among parts of the Chinese public may influence the future nuclear policy choices China’s leaders make. Nationalist sentiment is apparent, too, in an underlying belief that China needs more powerful nuclear forces not just because of military considerations but because such capabilities would win China international respect and contribute to strategic stability by making other countries less likely to pick a political fight with China.⁴⁷

At the official level, China has been more willing to place its SSBNs in the domestic and international spotlight in recent years. In October 2013, China’s most important official media outlets—including China Central Television (CCTV), the People’s Daily, the Xinhua News Agency, and the PLA Daily—all simultaneously released many high-profile reports and stories about the country’s SSBN fleet. This was the first time that Beijing officially showed off its sea-based nuclear capabilities through a massive media campaign.

Afterward, stories and commentary on the development of China’s SSBN fleet began to appear more frequently in both official and unofficial media reports. Chinese military experts often comment on this and related topics on CCTV channels, which further raises public awareness and interest. Due to the high level of secrecy regarding submarine operations, media coverage of Chinese SSBNs is not as intense as that surrounding, say, the country’s aircraft carrier fleets, but the former topic is receiving increasing levels of public attention. As a result, a considerable part of the general public sees the program as an important symbol of China’s growing hard power and international status.

Ultimately, Chinese decisionmakers face the challenge of separating practical security needs from the nationalistic desire to win more international respect and other nonsecurity considerations.

Ultimately, Chinese decisionmakers face the challenge of separating practical security needs from the nationalistic desire to win more international respect and other nonsecurity considerations. As U.S. scholar Charles Glaser points out, when a state engages in an arms race in response to an external threat, that state is acting rationally. By contrast, if the causes of an arms race are domestic, the state is acting suboptimally, and the consequences are likely to be more negative.⁴⁸ If China allows nationalistic sentiments to induce it to build a massive sea-based nuclear capability beyond any practical security needs, this could raise doubts in foreign countries about Beijing’s strategic intentions and contribute to an unnecessary, damaging strategic arms competition.

Notes

¹ Keir A. Lieber and Daryl G. Press, “The End of MAD? The Nuclear Dimension of U.S. Primacy,” International Security 30, no. 4 (2006): 7–44; Keir A. Lieber and Daryl G. Press, “U.S. Nuclear Primacy and the Future of the Chinese Deterrent,” China Security (Winter 2007): 66–89; Keir A. Lieber and Daryl G. Press, “The New Era of Counterforce: Technological Change and the Future of Nuclear Deterrence,” International Security 41, no. 4 (April 2017): 9–49.

² Wu Riqiang, “Certainty of Uncertainty: Nuclear Strategy With Chinese Characteristics,” Journal of Strategic Studies 36, no. 4 (2013).

³ Office of Naval Intelligence, “Worldwide Submarine Challenges” (Washington DC: Office of Naval Intelligence, 1997).

⁴ Wang Jin (王瑾), “Nuclear Submarines Vs. Aircraft Carriers: Which Should Be Prioritized” [核潜艇 & 航空母舰之优先理由], Ordnance Knowledge (兵器知识), no. 7 (2011).

⁵ Chen Fan (陈蕃), “The Second Nuclear Force: The History of China’s Nuclear Submarine Development” [第二核力量：中国核潜艇研制纪实], Shipboard Weapons (舰载武器) 4 (2007): 38-43; Lv Hong (红旅), “Sea-Based Nuclear Deterrent of the People's Navy” [人民海军的海基核威慑] Shipboard Weapons (舰载武器) 1 (2004): 28–34; and Yang Lianxin (杨连新), “Ballistic Missile Nuclear Submarine and National Security” [弹道导弹核潜艇与国家安全], Modern Ships (现代舰船) 9 (1995): 4–5.

⁶ Li Bin (李彬), “China’s Nuclear Strategy” [中国核战略辨析], World Economics and Politics (世界经济与政治) 9 (2006): 16–22, 24; Rong Yu (荣予) and Hong Yuan (洪源), “The Evolution of China’s Nuclear Strategy: From Anti-Nuclear Deterrence to Limited Deterrence” [从反核威慑战略到最低核威慑战略:中国核战略演进之路], Journal of Contemporary Asia-Pacific Studies (当代亚太) 3 (2009): 120–32.

⁷ Yang, “Ballistic Missile Nuclear Submarine and National Security” [弹道导弹核潜艇与国家安全].

⁸ Tao Chunbo (陶春波), “Analysis of Numerical Demands for Strategic Nuclear Submarines in Nuclear Powers” [核大国战略核潜艇需求量分析], Ship Engineering (船舶工程) 5 (1998): 56–58.

⁹ Li Bin (李彬) and Nie Hongyi (聂宏毅), “A Study of Sino-U.S. Strategic Stability” [中美战略稳定性的考察], World Economics and Politics (世界经济与政治) 2 (2008). The downside is that SSBNs need to remain safe during transit to the launch area. That said, road-mobile ICBMs also face a potential threat when relocating to a pre-designated launch pad or conducting operational patrols.

¹⁰ Wu Riqiang, “Survivability of China's Sea-Based Nuclear Forces,” Science & Global Security 19, no. 2 (2011): 93, 96, 104.

¹¹ Shou Xiaosong (寿晓松), The Science of Military Strategy [战略学] (Beijing: Military Science Press (军事科学出版社), 2013).

¹² Lyle J. Goldstein and Andrew S. Erickson, “China's Nuclear Force Modernization” (Newport, Rhode Island: Naval War College Center for Naval Warfare Studies, 2005).

¹³ Toshi Yoshihara and James R. Holmes, “China’s New Undersea Nuclear Deterrent: Strategy, Doctrine, and Capabilities,” Joint Forces Quarterly 50, no. 3 (2008).

¹⁴ Iskander Rehman, Murky Waters: Naval Nuclear Dynamics in the Indian Ocean (Washington DC: Carnegie Endowment for International Peace, 2015); Brendan Thomas-Noone and Rory Medcalf, “Nuclear-Armed Submarines in Indo-Pacific Asia: Stabiliser or Menace?,” Lowy Institute for International Policy, September 2015; Yoshihara and Holmes, “China’s New Undersea Nuclear Deterrent: Strategy, Doctrine, and Capabilities.”

¹⁵ Du Chaoping (杜朝平), “Indian ‘Nuclear Train’ Speeding Up in April” [印度“核战车”4月大提速], Paper 24, China National Defense News (中国国防报); and Zhang Jiegen (章节根), “Implications of Indian Nuclear Strategy to China’s Security Environment and South Asia Policy [印度核战略对中国安全环境及南亚政策的影响], Tongji University Journal - Social Science Section (同济大学学报(社会科学版) 22, no. 2 (2011): 65–71.

¹⁶ Author’s email correspondence with a former senior U.S. official and nuclear expert, January 2018.

¹⁷ Eric Heginbotham et al., “China’s Evolving Nuclear Deterrent: Major Drivers and Issues for the United States” (Santa Monica, CA: RAND Corporation, 2017).

¹⁸ State Council, “The Diversified Employment of China’s Armed Forces” [中国武装力量的多样化运用], The State Council Information Office (中国人民共和国国务院新闻办公室), http://www.china.org.cn/government/whitepaper/node_7181425.htm.

¹⁹ Zhang Jun’an (张钧安), “Statement of Counselor Zhang Jun’an of the Chinese Delegation on Nuclear Disarmament Issues at the First Committee of the 68th U.N. General Assembly” [中国代表团张钧安参赞在第68届联大一委关于核裁军问题的专题发言], Permanent Mission of the People’s Republic of China to the UN, http://www.china-un.org/chn/zgylhg/cjyjk/ldyw/t1092701.htm.

²⁰ Kristensen, Norris, and McKinzie “Chinese Nuclear Forces and U.S. Nuclear War Planning”; Paul H.B. Godwin, “Potential Chinese Responses to US Ballistic Missile Defense,” Report 43, Stimson/CNA NMD-China Project, January 17, 2002.

²¹ Based on the author’s private conversations with U.S. and British military experts, February 2016.

²² Scott Douglas Sagan, The Limits of Safety: Organizations, Accidents, and Nuclear Weapons, (Princeton, NJ: Princeton University Press, 1995); Charles Perrow, Normal Accidents: Living With High Risk Technologies (Princeton, NJ: Princeton University Press, 2011).

²³ Samuel Bell, “The Impact of the Type 094 Ballistic Missile Submarine on China’s Nuclear Policy,” Naval Postgraduate School, June 2009; and David J. Elkind, “American Nuclear Primacy: The End of MAD or a New START?,” Center for Strategic and International Studies, May 22, 2012.

²⁴ China’s 2013 defense white paper mentions that the Second Artillery Force “has a series of ‘Dong Feng’ ballistic missiles and ‘Chang Jian’ cruise missiles.” Therefore, the Ju Lang submarine-launched ballistic missiles are not managed by the Second Artillery. State Council, “The Diversified Employment of China's Armed Forces” (中国武装力量的多样化运用).

²⁵ “Expert: PLA Rocket Force Might Have Strategic Nuclear Submarine and Strategic Bomber [专家：火箭军或拥有战略核潜艇与战略轰炸机], China News Network (中国新闻网), January 7, 2016.

²⁶ There are other important questions about the relationship between the land-based nuclear missiles of the PLA Rocket Force and the SSBNs of the PLA Navy. For instance, will some missiles be reassigned to the newly established theater commands during wartime? How will targeting coordination between the SSBN force and the Rocket Force be carried out? These are important issues, but they are not addressed in this research due to a lack of authoritative information. State Council, “The Diversified Employment of China's Armed Forces” (中国武装力量的多样化运用].

²⁷ Dan Plesch and John Ainslie, “Trident: Strategic Dependence & Sovereignty,” SOAS University of London, 2016.

²⁸ Progress on the communications front is discussed later in the report in the section on the ASW threats faced by China’s SSBNs. Office of the Secretary of Defense, Annual Report to Congress: Military and Security Developments Involving the People’s Republic of China, 2015 (Washington DC: Office of the Secretary of Defense, 2015).

²⁹ Linton Brooks, “Strategic Stability and Submarine Operations: Lessons From the Cold War,” in Confidence-Building and Maritime Strategic Stability in the Asia-Pacific (Beijing, China: Carnegie–Tsinghua Center for Global Policy, February 11, 2015).

³⁰ Malcolm Chalmers, “Continuous-at-sea Deterrence: Costs and Alternatives,” Royal United Services Institute Briefing Paper, 2010; Andrew Futter, “Trident Replacement and UK Nuclear Deterrence: Requirements in an Uncertain Future,” RUSI Journal 160, no. 5 (2015).

³¹ Fiona S. Cunningham and M. Taylor Fravel, “Assuring Assured Retaliation: China’s Nuclear Posture and US-China Strategic Stability,” International Security 40, no. 2 (2015): 7–50.

³² Kristensen and Norris, “Chinese Nuclear Forces, 2018.”

³³ According to the assessment of Hans M. Kristensen and Robert S. Norris, the total number of DF-5A, DF-5B, and DF-31A missile launchers is about fifty-two.

³⁴ That said, if the JL-2 SLBM can, as some sources claim, carry—or be adapted to carry—more than one warhead, the number of warheads that could reach the continental United States may increase even more.

³⁵ Richard Weitz, “US-China Commission Underscores Growth in Chinese Nuclear Strike Potential,” Second Line of Defense, January 9, 2013.

³⁶ Lyle J. Goldstein, “China Prepares to Ramp Up Its Shipbuilding Process,” National Interest, April 02, 2017.

³⁷ Zhang Cheng (张程), “China’s Rarely Seen Nuclear Submarine Factory Revealed, Hong Kong Media: Can Build 5-6 Nuclear Submarines Simultaneously” [中国核潜艇工厂罕见曝光 港媒：可同时建造5至6艘核潜艇], Reference News (参考消息), April 20, 2017. “Q&A: China’s Newspaper Industry,” BBC News, January 11, 2013, http://www.bbc.com/news/business-20970543.

³⁸ Christopher Carlson, “Why Everyone Is Wrong About China’s Next-Gen Submarines,” National Interest, July 23, 2017, http://nationalinterest.org/feature/why-everyone-wrong-about-chinas-next-gen-submarines-21631.

³⁹ For a further discussion about foreign influence over China’s decision to start its SSBN program, see, for example: Tong Zhao, “China’s Sea-Based Nuclear Deterrent,” in Regional Voices on the Challenges of Nuclear Deterrence Stability in Southern Asia, ed. Ashley J. Tellis (Washington, DC: Carnegie Endowment for International Peace, 2016).

⁴⁰ Ling Xiang (凌翔), “Birth of China’s Nuclear Submarine” [中国核潜艇诞生记].

⁴¹ Goldstein and Erickson.

⁴² Shi Changxue (施昌学), Naval Commander Liu Huaqing [海军司令刘华清] (Beijing: Long March Press (长征出版社), 2013).

⁴³ Guo Wei (郭维), Yang Qingxuan (杨清轩), and Su Qiang (苏强), “Research on the Trend of Development of Foreign Ballistic Missile Nuclear Submarines” [国外弹道导弹核潜艇发展趋势研究], Ship Science and Technology (舰船科学技术) 37, no. 7 (2015): 233–237.

⁴⁴ Yang, “Ballistic Missile Nuclear Submarine and National Security.”

⁴⁵ Tai Ming Cheung, “The Current State of Defense Innovation in China and Future Prospects,” IGCC Defense Innovation Briefs, no. 1 (2014), 5.

⁴⁶ “Editorial: Strengthen Strategic Nuclear Capability: China Must Not Hesitate” [社评：加强战略核力量，中国不可患得患失], Global Times (环球时报), December 23, 2016; “Editorial: Both China's Defense Spending and Strategic Nuclear Capablities Are Not Enough” [社评：中国的军费和战略核力量都还不够], Global Times (环球时报), December 14, 2016.

⁴⁷ “Editorial: China Should Deploy Df-41 Missile as Soon as Possible to Counter U.S. Provocation” [评论：中国应尽早列装东风41导弹 削弱美挑衅气势], Global Times (环球时报), December 05, 2016; “Editorial: Df-41 Reportedly Deployed, China Will Gain More Respect” [社评：‘东风-41’ 被传列装，中国将获更多尊重], Global Times (环球时报), January 24, 2017.

⁴⁸ Charles L. Glaser, “The Causes and Consequences of Arms Races,” Annual Review of Political Science 3, no. 1 (2000).