Eric Gomez reviews the implications of China’s growing nuclear arsenal.

The nuclear aspect of US-China superpower competition is garnering increased attention. China’s longstanding nuclear modernisation effort leapt into the headlines in 2021 with the discovery of three under-construction silo fields that could host up to 120 silos apiece. The Chinese also successfully tested a hypersonic fractional orbital bombardment system. What nuclear modernisation steps is China taking and what are the strategic implications for the United States?

Answering the first part of that question is relatively easy, but it is harder to accurately predict the nuclear strategy that China’s larger and more sophisticated arsenal will implement. What is certain is the nuclear aspect of US-China competition is growing in importance.

In his March 2022 testimony to Congress, the head of US Strategic Command warned that the US Department of Defense would have to take “immediate and significant planning and/or capability shifts” to respond.

Small but deadly
Since becoming a nuclear power in 1964, China’s nuclear arsenal has been characterised by its small size and emphasis on retaliation rather than warfighting. The main purpose of nuclear weapons in the minds of Mao and other leaders was to prevent nuclear coercion and first use of nuclear weapons against China.

Instead of engaging in nuclear arms racing, China maintained a small and relatively unsophisticated arsenal that was controlled by a no first use (NFU) doctrine.

Assured Retaliation
China’s approach to nuclear deterrence is commonly known as assured retaliation. China will ride out a nuclear attack and mount an effective counterattack rather than using nuclear weapons first. The prospect of an assured second strike is what prevents an adversary from first use.

Authoritative Chinese documents such as the 2020 edition of the Science of Military Strategy and recent defence White Papers insist that China retains a NFU doctrine and a “lean and effective” nuclear deterrent. However, recent nuclear modernisation activities have rattled Washington.

Modernisation
Prior to the summer 2021 silo field discovery, China’s nuclear modernisation activities since 2000 focused on improving survivability and flexibility. The number of nuclear warheads grew, but modernisation emphasised qualitative improvements rather than expanding the arsenal.

According to estimates by The Bulletin of The Atomic Scientists, China’s arsenal grew from roughly 240 warheads in 2010 to 350 warheads in 2021.

Some of China’s intercontinental ballistic missiles (ICBMs), namely the DF-5B and the newer DF-41, added multiple independent reentry vehicles to improve the ability of individual missiles to defeat missile defences.

Road-mobile ICBMs such as the DF-31A and DF-41 enhance survivability by being harder to find and destroy than missiles in immobile silos. The vehicle used on the DF-31AG may have some limited off-road capability and the ability to fire from unprepared launch sites.

China has also made progress toward fielding a nuclear triad with the addition of the Type 094 submarine and reconstitution of the air force’s nuclear mission.

Finally, China also improved its theatre nuclear forces with the addition of the DF-26 intermediate-range ballistic missile that can use either a nuclear or convention warhead.

The discovery of three silo fields capable of hosting 360 missiles in total is an important development because it signals a potential shift in China’s approach to nuclear modernisation – from qualitative improvement towards numeric expansion.

It is difficult to predict how many silos China will end up constructing, what missiles will fill them, and how many warheads they will carry. There is a wide range of options that China could take with the silo fields, and any assessment of long-term plans and intentions will be speculative.

The important take away is the potential for a shift in China’s nuclear modernisation strategy – from improving technology to increasing numbers.

Strategic implications
Although it is difficult to know for sure if China’s nuclear modernisation efforts portend a broader shift in its approach to nuclear strategy, thinking through various options is a valuable exercise.

A qualitative and quantitative expansion of China’s nuclear arsenal could be consistent with a strategy of assured retaliation. China could retain its emphasis on deterring nuclear first use and adhere to a restrictive nuclear doctrine with a larger arsenal.

Beijing lives in a rough nuclear neighbourhood. Four nuclear-armed states border China (India, North Korea, Pakistan, and Russia) and the US has long extended its nuclear umbrella over regional allies. While Beijing views the US as its primary strategic threat, it still must plan against multiple nuclear-armed powers even if many of them are currently friendly.

Non-nuclear challenges
Moreover, Chinese officials and strategists are generally concerned about the growth of non-nuclear threats to China’s nuclear forces, particularly missile defence and conventional precision strike capabilities. These weapons could enable the US to degrade China’s nuclear deterrent without using nuclear weapons.

Chinese threat perceptions overestimate US capabilities but concerns about non-nuclear threats to nuclear forces make regular appearances in Chinese writings and strategic dialogues. American interest in low-yield nuclear weapons has also raised concerns in China about the potential for US limited nuclear use.

Changing strategy
In this context, a significant expansion of China’s silo-based ICBM force could be an effective way to keep the arsenal ‘lean and effective’ despite growing threats. Silos are easy to target – but because they are hardened, they cannot be easily destroyed by conventional weapons. The location of the silo fields in China’s interior also puts them out of range of most US conventional weapons.

A more pessimistic assessment of China’s nuclear modernisation activities is that Beijing has fundamentally changed its nuclear strategy, and has adopted a more aggressive approach that demands a larger, flexible arsenal.

This would imply either an abandonment of NFU or significantly more ambiguity around its conditions. Chinese nuclear doctrine already allows for counterattacks against military targets, but larger stocks of theatre nuclear weapons give Beijing more options for limited nuclear use.

Several US analysts have also raised the possibility that China could use nuclear stalemate as cover for more conventional aggression.

New capabilities
Authoritative Chinese statements on nuclear strategy, such as the 2019 Defence White Paper and 2020 Science of Military Strategy, give no indication that China has fundamentally rethought assured retaliation. However, China’s new nuclear capabilities give it the option to change its strategy in ways that would not have been possible only a few years ago.

Even if China does not have the intention to move away from assured retaliation, it has the capacity to do so.

Regardless of China’s nuclear strategy, Washington has already signalled that it regards Beijing’s actions as threatening. China’s nuclear developments will most likely justify the current US nuclear modernisation plan – and could increase calls to add new capabilities.

The US has also been unwilling to consider missile defence limitations, despite the role of those capabilities in China’s threat perceptions.

US response
The US should proceed very carefully with its reaction to China’s recent nuclear modernisation activities. Washington should not abandon efforts to engage Beijing on arms control and nuclear stability issues.

However, China’s reluctance to engage in talks at the official level is a source of frustration in Washington. Furthermore, the US should actively consider how its approach to conventional military strategy could increase or decrease the risk of nuclear escalation, both intentional and inadvertent.

A larger and more advanced Chinese nuclear arsenal does not automatically mean that the Americans can no longer deter first use by China. Analysts should beware threat inflation – and think calmly and carefully about ways to prevent competition from devolving into outright conflict. China’s changing nuclear arsenal will complicate this effort, but it does not make it a lost cause.

Eric Gomez is Director of Defence Policy Studies at the Cato Institute. His research focuses on nuclear deterrence, arms control, and inadvertent escalation in East Asia.

Image:
Upper stage of the DF-5B intercontinental range ballistic missile on parade in Beijing in 2015. The DF-5B can carry multiple nuclear warheads.

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