China’s expanding nuclear forces

9 August 2021

China is vastly expanding its nuclear forces at an unprecedented rate. Recent discoveries of two new ICBM fields totalling around 230 new missile silos have raised important questions about the future of China’s nuclear posture. Beijing represents a clear security challenge to the United States and its partners and allies in the region — increased Chinese aggression and a rapidly modernising military make that clear. But it is often misunderstood how nuclear weapons fit into China’s military strategy. While the specific details about these silos may not be immediately clear, an understanding of China’s thoughts on nuclear weapons and its motivations can help intelligently evaluate the issue.

China’s approach to nuclear weapons

China’s nuclear strategy evolved in quite a different manner than either the United States or Soviet Union, and its nuclear strategy is often foreign to US nuclear analysts. China initially developed nuclear weapons to accomplish two primary objectives, deterring a nuclear attack and preventing nuclear coercion. To do this, China’s leaders maintained that it needed a relatively small arsenal, needing only to be able to survive a first strike and retaliate. They didn’t view the threshold of damage it needed to inflict on an adversary as very high and found a large nuclear arsenal to be unnecessary. This differed substantially from the strategies of states like the United States and the Soviet Union, both of whom envisioned using nuclear weapons to destroy their adversary's nuclear arsenal or escalating to nuclear use to overcome conventional inferiority in specific theatres.

China never adopted any form of direct warfighting objectives for its nuclear forces, and internal texts on the subject consistently only describe one campaign for nuclear use, the nuclear counterattack campaign. Doctrinally-informed, authoritative documents such as the Science of Military Strategy discuss the role of nuclear deterrence as preventing a nuclear attack in peacetime and preventing conventional wars from escalating into nuclear conflict during wartime. It was thought that the vast destructive power of nuclear weapons and the inherent escalation risks made them largely unusable in conflict; conventional conflicts would be where wars were won or lost.

If China adopts a launch-on-warning posture that could cause substantial damage to the United States regardless of arsenal size, nuclear weapons are also unlikely to be enough to deter conventional conflicts outside the United States.

In this sense, China’s nuclear strategy developed around checking nuclear use by an adversary by maintaining a credible capacity to retaliate with enough pain to make the adversary rethink any plans to use nuclear weapons. The bulk of its actual warfighting capability was put into a vast array of conventional forces that would be more usable in conflict and could be employed to aggressively seize the initiative. In this way, China sought to check the nuclear level while fighting and winning wars at lower levels of escalation.

However, China’s nuclear arsenal has arguably never been able to meet this objective of assured retaliation comfortably. Chinese strategists have expressed concerns as to the vulnerabilities of their force, especially in light of technological advances in warfare. Estimates of China's nuclear forces typically ranged from around 200-350 warheads — several folds smaller than the vast US nuclear arsenal. Precision conventional forces and programs such as Conventional Prompt Global Strike, coupled with advancements in Intelligence, Surveillance, and Reconnaissance (ISR) leave China’s nuclear forces more vulnerable than ever to both conventional and nuclear forces. Meanwhile, US ballistic missile defence threatens to intercept any surviving warheads the People's Liberation Army (PLA) could use to retaliate during a counterattack.

Continued nuclear expansion

As China seeks to build a world-class military, the expansion of its nuclear forces should not come as a surprise. With tensions growing in the region, ensuring that its ability to retaliate and credibly deter an adversary’s nuclear use is functional (and perceived as such by China’s adversaries) likely takes on greater importance. Building additional silos likely serves to ensure it maintains an assured retaliatory capability — and ensure that the United States shares this perception.

This expansion is not entirely new, China’s nuclear forces have been growing and modernising for some time, though the most notable changes have been qualitative up to this point. Nor is expansion likely to stop at these silos. Even if no more silos are built — an open question at this point — China is still likely to proliferate further as it continues building towards a nuclear triad. As China builds Type 096 SSBNs and H-20 strategic bombers, its nuclear forces will grow as it outfits these new systems.

While there have been some assertions that building silos wouldn't increase Chinese nuclear force survivability, and instead would only be useful as a first-strike weapon, this is unlikely to be the case. For one, a substantial concern regarding China's nuclear survivability has been its vulnerability to conventional counterforce capabilities, a vulnerability mitigated by hardened, silo-based weapons. While most of China’s mobile nuclear forces are exceptionally survivable based on mobility and concealment, they aren’t hardened like silo-based forces are, and if found could be targeted by conventional weapons as well as nuclear weapons. Diversifying towards hardened silos that would need to be targeted with nuclear weapons and are out of range of current US conventional weapons is a prudent move towards enhancing nuclear force survivability.

Further, with new silos, the United States would need to target hundreds of additional locations to dismantle China’s nuclear forces in a counterforce strike. Assuming a 2:1 targeting ratio, this would mean a strike of nearly 500 US nuclear weapons would be necessary to destroy these silos alone. This expends US ordnance, pulls attention and ordnance away from other nuclear forces or key targets, and forces an unambiguous, massive nuclear strike to destroy China’s nuclear retaliatory force. Since many of the same arguments are made for US ICBMs, it’s hard to see why analysts would assume that this logic would not hold for China, but work for the United States.

Unanswered questions and new force compositions

While understanding the drivers of Chinese nuclear strategy is important, this vast expansion still represents a substantial shift away from China's previous force composition. Several questions remain unanswered and analysts should avoid drawing too-firm conclusions on the implications from limited information. However, some form of a shift in doctrine may be likely, though such shifts are unlikely to completely reinvent the basis of Chinese nuclear strategy.

One of the more interesting discussions in recent years on Chinese nuclear forces has been a potential shift to a launch-on-warning posture. Official documents such as the Science of Military Strategy have discussed this prospect, claiming it would be consistent with their no first use policy, as an attack would already be incoming and unambiguous. Per some Chinese strategists' views, this would greatly increase the survivability of China's nuclear forces. If China launched its nuclear forces before an incoming attack had the chance to destroy them, a far greater number of Chinese nuclear forces would survive and retaliate against the adversary.

While the supporting infrastructure to do so may not be immediately available, China has been building a space-based early warning system that could support such a shift by providing early detection of an adversary’s missiles. A silo field is well-oriented for such a posture, especially when using the solid-fueled DF-41s that are likely to be deployed at these new silos as opposed to China's older, liquid-fueled DF-5s that would take longer to fuel and launch. If China was to shift to a launch-on-warning posture, building large numbers of silos would be a prudent move to support this.

This would require a departure from another historic mode of restraint, China’s warhead handling procedures. China has typically kept its warheads unmated and stored separately from its missiles, perhaps one of the more convincing aspects of its no-first-use policy. A shift to launch-on-warning would require a change in China’s warhead handling policy, keeping siloed weapons always mated and on high alert. This was already a hurdle that China would have to face if it began utilising its expanding SSBN force to maintain a continuous, at-sea deterrent.

It should be stated, a shift to a Chinese counterforce posture remains unlikely. However, as China’s nuclear forces expand, new options for how their nuclear forces could be employed will become open to the PRC that should be considered by analysts, even if these options were not the intent behind such expansions initially.

While a shift to launch-on-warning is quite plausible and has been considered by the PLA, these potential changes are far from certain. A variety of theories exist as to the intent behind these silos. Other experts have hypothesised that this could be similar to the Cold War-era ‘shell game’ concept, in which a small number of weapons are scattered and transferred between a large number of silos, forcing the adversary to target all the silos for lack of knowledge as to which ones contain missiles. While all of these theories have merit, until further information is available, analysts cannot say definitively what the intentions are. What is certain is that a greatly expanded number of silos will significantly increase China’s assured retaliatory capability and give China new options should it opt to adopt further doctrinal changes.

Nuclear growth, conventional risks

While China’s nuclear force expansion raises a lot of questions and the potential for worrying posture shifts, the primary cause of concern may be how this expanding nuclear force could affect China’s conventional aims. If China seeks to be able to win local, conventional conflicts, ensuring that it can check nuclear use and deter intervention is a prudent move for the PLA. If China feels secure in its nuclear retaliatory capability, and that it holds a credible capacity to cause damage that the United States isn’t willing to bear, then China may feel more secure about engaging in regional, conventional conflicts.

Although the United States must ensure it maintains a strong, credible nuclear deterrent, nuclear weapons alone may not be the key to deterring nuclear risks in the Pacific theatre. Moreover, if China adopts a launch-on-warning posture that could cause substantial damage to the United States regardless of arsenal size, nuclear weapons are also unlikely to be enough to deter conventional conflicts outside the United States. A greater focus on conventional deterrence-by-denial in the Indo-Pacific may be a more effective response to China’s expanding nuclear forces than any form of quantitative nuclear expansion by the United States. Ensuring that China cannot win a conventional conflict in the theatre should be a top priority in US defence planning.

A conventional conflict between the US and China could carry substantial risks of escalation to the nuclear level, and the key to preventing these nuclear risks and ensuring a free and open Indo-Pacific does not lie in nuclear arms racing. Deterrence is not so neatly separated between conventional and nuclear forces; preventing conflict and nuclear risks in the Indo-Pacific are intrinsically intertwined. China’s vast nuclear expansion carries several concerning implications and may create posture changes that should be examined thoroughly. But looking at the issue and responding purely through the nuclear lens is unlikely to be the correct approach.

DISCLAIMER: All views expressed are those of the writer and do not necessarily represent that of the 9DASHLINE.com platform.

Author biography

Gerald C. Brown is an analyst with Valiant Integrated Services focusing on nuclear deterrence and East Asian security. All views expressed here are his own. Image credit: Wikipedia.