Drawing a line between conventional and nuclear weapons in China

China possesses one of world’s largest and most sophisticated ballistic missile forces. This force, which includes both conventional and nuclear-armed missiles, is controlled by the Second Artillery Corps of the People’s Liberation Army. Public accounts of China’s missile forces suggest that these conventional and nuclear missiles are operationally and geographically entangled, which poses a threat of inadvertent escalation and instability during a crisis.

Second Artillery bases may operate both conventional and nuclear missiles, and even some missile systems—such as the road-mobile DF-21—accommodate both missile types. In addition to co-locating, China’s ballistic and nuclear missiles may share the same support capabilities and facilities, including the same command and control systems.

Historically, given its lack of an early warning system, absence of more-survivable deployment options such as advanced ballistic missile submarines, and the country’s comparatively reserved nuclear posture exemplified by its declared no-first-use policy, China has relied upon stockpile and operational opacity to ensure the survivability of its relatively small nuclear force. By obscuring information—such as how many weapons it possesses, where those weapons are deployed, and the size of its fissile material stockpiles—China can use quantitative and geographic ambiguity to confound attempts by an adversary to preemptively eliminate China’s nuclear force.

Ambiguity, however, increases the risks of misperception. In order to help alleviate these risks, China should consider a policy of disentanglement that would include a pledge to physically separate its conventional and nuclear missiles, as well as to develop separate supporting capabilities for each type of missile.

The fog of war. In a conflict, it may be difficult for the United States or other adversaries to discriminate between China’s conventional and nuclear forces. An attempt to target conventional missiles may require targeting of bases that also house nuclear missiles, or targeting of centralized support infrastructure such as command and control facilities. Chinese decision makers could misinterpret such targeting as an attempt to preemptively eliminate China’s nuclear force.

The United States may see a strike against centralized facilities as particularly attractive compared with the difficulty of finding, tracking, and destroying multiple deployed mobile missiles. Even if Beijing were to correctly conclude that a US strike was genuinely intended to only target China’s conventional missiles, such strikes might nonetheless represent a threat to China’s nuclear deterrent to the extent that Beijing relies on the same systems and personnel for conventional and nuclear command and control. Either way, such a strike would certainly be perceived as highly provocative and escalatory.

Military doctrines such as the Pentagon’s Air-Sea Battle concept (now called the Joint Concept for Access and Maneuver in the Global Commons) and China’s Anti-Access/Area-Denial capabilities, both of which emphasize the role of China’s conventional ballistic missile force, accentuate the risk of escalation. In a conflict, it is possible that China would opt for first use of these missiles, or that the United States would seek to preemptively neutralize these missiles.

These risks could be further exacerbated by the interplay between US Conventional Prompt Global Strike (CPGS) weapons and reports of future Chinese early warning systems coupled with a hair-trigger alert for nuclear weapons. For example, the launch of a CPGS weapon would likely follow, or appear to follow, a ballistic trajectory for at least part of its flight path—which, if detected by a Chinese early warning system, could be misinterpreted as a nuclear-armed ballistic missile.

Finally, both China’s anti-satellite weapon and its conventional anti-ship ballistic missile are based on the nuclear-capable DF-21 missile, which could exacerbate the potential for misunderstandings in the fog of war. For example, US forces might misinterpret the readying of a conventional DF-21 as preparation to launch a nuclear strike.

Separate deployments and infrastructure. To address these entanglement risks, China should consider a comprehensive policy of disentanglement, separating deployment and control of its conventional-armed ballistic missile forces from those of its nuclear-armed ones. First, conventional and nuclear forces should be deployed at different bases. Further, the Second Artillery should develop independent support systems, including command and control arrangements and training doctrines.

Aside from its history of opacity about its nuclear force, China’s extensive use of road-mobile ballistic missiles presents perhaps the greatest challenge to a verifiable disentanglement policy. Unlike silo-based missiles, mobile ones can be relocated. Verifying the disentanglement of mobile missiles can be accomplished by applying features of the monitoring regimes for mobile missiles used in the START I and New START agreements between the United States and the Soviet Union/Russia to limit those countries’ deployed nuclear forces. Drawing on the lessons of those agreements, China could establish single, non-overlapping deployment zones around each base. Mobile missiles dispersed as part of a training exercise or an actual deployment could only move within the deployment zones of their respective bases. To further facilitate verification, China could also deploy mobile missiles with readily distinguishable features, such as visually unique vehicles to transport and launch mobile missiles, and could agree not to use certain concealment measures at some of its missile bases.

Facilitating verification. Two major issues complicate a disentanglement policy: the ability of the United States and other states to confidently verify such a policy, and disentanglement’s impact on the survivability of China’s nuclear forces. A disentanglement policy must be reasonably verifiable through national technical means, such as satellites, in order to facilitate target discrimination by potential adversaries. China’s nuclear force is smaller and less widely distributed than Russia’s, so it should be easier to monitor. New START has successfully verified restrictions on Russian mobile missiles, despite eschewing and consolidating many of the intrusive on-site inspection and monitoring activities that previous accords applied to manufacturing, deployment, and movement of mobile missiles.

In order to alleviate concerns that greater transparency would erode survivability, China might opt for a policy of partial geographic transparency by identifying the locations of only those bases deploying conventionally armed ballistic missiles, while still maintaining ambiguity about its nuclear deployments.

Potential adversaries could take comfort that a disentanglement policy would be self-enforcing, because, once proclaimed, it would enhance China’s nuclear force survivability against an inadvertent strike. A violation of such a policy would place all China’s missiles at risk by forcing adversaries to assume that, because missiles are no longer disentangled, any missile might be a desired conventional target.

Maintaining survivability. The disentanglement of conventional and nuclear ballistic missile forces would entail a degree of transparency that China has heretofore been reluctant to provide, because opacity is an essential feature of China’s force survivability. The twin goals of survivability and verification at first seem contradictory. However, they exist in different contexts and with different requirements. Effective peacetime verification provides confidence that conventional and nuclear missiles are not based together. However, in a crisis, the tools used to verify disentanglement in peacetime would not help pinpoint the exact location of an already dispersed mobile missile within a large deployment zone. For example, Soviet deployment zones established to monitor mobile missiles under START I were 125,000 square miles, providing ample space for mobile missiles to hide during operational dispersals in a crisis.

The difficulty of the US military in tracking Iraqi mobile SCUD missiles during the Gulf War demonstrated the challenges of wartime targeting. Also, past technical analysis has demonstrated that simple countermeasures could hamper tracking of already deployed mobile missiles by, for instance, a space-based radar tracking and surveillance system.

To some degree, separate deployment of conventional and nuclear missiles would reflect the different roles of these weapons. Indeed, early intelligence estimates reported that China first deployed its conventional DF-21 missiles along its borders in order to ensure maximum target coverage. On the other hand, the greater range of China’s nuclear-armed intercontinental ballistic missiles (ICBMs) allows them to be launched from anywhere within the country’s borders and still hit targets necessary for strategic deterrence. Deploying its nuclear missiles away from its borders and coastline would help China ensure the survivability of its limited force, sheltering them behind air defense systems and so-called Anti-Access/Area-Denial capabilities—which could be used to keep US forces, including any possible boost-phase missile defense systems, beyond striking distance of Chinese territory.

Moving toward transparency. Realization of a disentanglement policy would likely face strong political and military obstacles in China, especially given legitimate concerns about force survivability and overall strategic stability. However, trends in China’s nuclear forces augur toward a future strategic environment more amenable to transparency, and such a policy could be implemented in conjunction with other measures designed to address Chinese and American concerns about stability.

As China’s ongoing nuclear modernization program enhances the survivability of its nuclear force, it may provide Beijing with more confidence in pursuing nuclear transparency without fear of eroding its deterrent credibility. China is transitioning to a force of more reliable solid-fueled mobile missiles while possibly working toward the eventual deployment of a survivable nuclear-powered ballistic missile submarine (SSBN) force. While China still has much progress to make on the technical front, these developments may work in concert to lessen Beijing’s reliance on geographic and operational ambiguity.

It is also likely that, until China acquires an assured retaliatory capability, Beijing will view the benefits to stability of a disentanglement policy, however real and desirable for both sides, as accruing disproportionately to the United States. To address this potential asymmetry, a disentanglement policy might be considered as part of a suite of agreements designed to increase strategic stability between the two countries and limit the chance of inadvertent escalation in a crisis. Such tradeoffs could include measures to address Chinese concerns regarding US ballistic missile defense systems, Conventional Prompt Global Strike weapons, or revitalized anti-submarine warfare capabilities.

The difficulty in forging and implementing such proposals does not make them unworthy of pursuing. Future progress on arms control agreements, either in pursuit of global disarmament or as a means of enhancing stability, will ultimately need to address Chinese forces. Even if these agreements are far off, and may need to be forged in different political and strategic environments, it is worth considering now what measures merit exploring. A disentanglement policy and its attendant transparency could represent the first step toward more formal and comprehensive future agreements and help lessen the risks of the world’s most dangerous weapons.