The Maritime Leg of China’s Naval Deterrent is Coming of Age

Over the past decade China has enhanced its nuclear weapons programmes, with comprehensive investment in warhead design, test, manufacture and delivery capabilities. This has happened with limited fanfare, and relatively little awareness among Western publics more concerned with conflict in Ukraine and the Middle East. But nonetheless China’s long march towards being if not the nuclear superpower than a nuclear superpower has been relentless.

China’s nuclear warhead stockpile is a distant third compared to Russia and the US. Even were it to double its stockpile over the next 10 years – a challenging but realistic goal based on assessments of the speed at which it can extract plutonium from spent fuel in its fast breeder reactors – it would still remain a long way off the absolute warhead numbers of the US and Russia.

But size isn’t everything. New Strategic Arms Reduction Treaty restrictions that constrain US and Russian deployments will likely wane, but even so, there is limited room for additional warhead deployments in their arsenals. China could approach near parity by having a higher proportion of a stockpile of 1,200–1,500 warheads operationally deployed on missiles. Another consideration is that modern warheads on modern delivery systems – such as hypersonic glide vehicles mounted on fractional orbital bombardment systems – have the potential to give China an overall nuclear capability that belies the numerical size of its arsenal.

Survivability as China’s Main Current Priority

Improving the survivability of China’s arsenal to assure a second-strike capability has been China’s clear priority over the past decade. The bulk of its nuclear force is land-based and this component has seen considerable improvement. China has apparently fielded 100 DF-31 and DF-41 inter-continental ballistic missiles in silos, along with road-mobile variants of the same missiles. These solid-fuel missiles can be employed quicker than heavier liquid-fuel missiles like DF-5. The decision to trade throw weight for prompt employment could be an indicator of the perceived threat from US strike capabilities which, according to some Chinese analysts, seriously constrain the survivability of China’s arsenal. The construction of hundreds of additional silos – many unfilled – could compel an adversary to expend missiles on decoys, and China’s concurrent expansion of road-mobile missile launchers exploits its geographical expanse to boost survivability. While the air component of its triad is the smallest, the Xian H-20 strategic bomber, in development for over 15 years and probably entering service imminently, will give China a low-observable long-range nuclear strike platform.

In early 2026, the US publicly accused China of conducting covert underground nuclear testing in Xinjiang. Specifically it claimed that in 2020, China conducted a test using ‘seismic-decoupling’: the technical term for blowing up a nuclear device inside a large cavity, normally carved out of salt residue, that substantially reduces its seismic signature making it less likely for international monitoring to detect it as a nuclear explosion. China denied this, and the wider global response was muted. The question of whether China felt like it had been ‘caught out’ by the US, or felt emboldened by the lack of international response, is unanswered.

China’s SLBM Capability Comes of Age

The US might have hoped for more from its accusation of seismically-decoupled nuclear testing, but the 6 July submarine-launched ballistic missile (SLBM) test is seismic in its own way. China described the test firing as ‘a routine arrangement’ and has not commented on what exactly was tested. It is widely assumed it was the new JL-3 missile, previously assessed to have a range in the order of 10,000 km, and to be intended to be integrated onto its new Type 096 nuclear-armed submarines (SSBNs).

The missile flew 7,500 km to its target, although the trajectory is unknown, as is the mass of its inert warhead which may have been less than an operational loadout. Test firings often use a lofted trajectory with around half the range it would have in normal use. As such the range of this missile could be well over 10,000 km, closer to 15,000 km.

It is almost certain that JL-3 will have multiple payload options. Its JL-2 predecessor can be configured with either a single megaton warhead or with multiple lighter manoeuvrable re-entry vehicles. If the single dummy was a stand-in for a larger, megaton-yield warhead, then the test probably does demonstrate the SLBM’s ‘real’ range.

In contrast to its land-based nuclear component, the capability of China’s SSBN fleet has been modest. As its current fleet of six Type 094s are relatively noisy boats that could not reliably evade detection passing through chokepoints such as the Bashi Channel between the East and South China Seas, the assumption has been that they would be confined to the South China Sea, mimicking Russia’s ‘bastion’ strategy of protecting its SSBNs with layers of air, surface and subsurface assets. With the limited range of the in-service JL-2, the fleet would run a high risk of detection if it attempted to hold targets in the continental US at threat.

In contrast, according to presentations provided by the People's Liberation Army officers, China’s new Type 096 SSBNs will use pump jets and hybrid turboelectric drives resulting in a much lower acoustic signature than their predecessors. These are the submarines intended to carry JL-3. This pairing will change the existing dynamic. The longer range of the JL-3 would allow it to be employed against continental US targets from well within the first island chain. Official aviation alerts issued by the People’s Liberation Army ahead of the test are consistent with the missile being launched from areas which, in wartime, would be inside one of China’s maritime bastions.

It is also possible that this test demonstrates a capability to hit far further than the west coast of the US from positions far closer to China's shores. If so, China's SSBN capability will have come of age, and will have transformed from an expensive luxury to a true strategic asset.

Timing is Everything

The timing of the test is not inconsequential. The joint China–Russia naval exercise that it opened will have been planned long in advance, and it is likely that the opportunity to send a clear message regarding China’s future deterrent in the immediate aftermath of America 250 was a factor. This builds on the underlying message of President Xi Jinping’s narrative to the US: that China is becoming the dominant power in a new world order, and that the US must respect and accept this lest it wishes to drift into conflict where it will no longer be assuredly dominant.

China may have viewed it as serendipitous that its planning for its test culminated on the day Australia signed a mutual defence treaty with Fiji – a pact that has been negotiated at pace, largely behind closed doors, and that could form a framework for similar agreements between Australia and regional allies. China was quick to give measured public criticism of the agreement, citing the importance of larger powers recognising the autonomy of Pacific Island states.

There is also a potential downside for China. As well as the expected criticism from Australia, Japan and New Zealand, the Solomon Islands, one of China’s closest Pacific Island partners, has been unusually critical, stating that ‘China is a good friend of the Solomon Islands, but this is not something a friend does’. China’s gesture of strength may be the event that coalesces smaller Pacific states around the notion that, while they are happy to seek individual partnerships and co-operation with larger regional and global powers, they do not want to provide the global stage for demonstrations of Great Power military competition – which could strengthen regional co-operation to provide more of a bulwark to Chinese expansionism.

Stabilisation of the China–US Balance as a Driver for Wider Insecurity

The consequences of this growth of Chinese nuclear capability are mixed. Chinese expansion of nuclear forces to improve limited survivability – especially in the context of improving US conventional deep strike capability – was a strategic inevitability. In one sense, a modern, capable SSBN fleet with a capable SLBM loadout better promotes stability than any further expansion of silo-based systems. The presence of large amounts of large payload systems in static locations drives the risk of pre-emption by both sides: They are easy to target in a pre-emptive strike, and they present China with a ‘use it or lose it’ dilemma.

However, the greater survivability of the Chinese nuclear arsenal also has the potential to undermine US extended nuclear deterrence, which has always depended upon the US’s capacity for damage limitation and thus holds a margin of superiority versus both China and Russia. In effect, the US has avoided the question of whether it really would trade ‘Washington for Bonn’ by maintaining a relative advantage that meant it was possible, if not certain, that it would not have to do so. Paradoxically, strategic stability between the US and a major global adversary could lend itself to regional instability.

© RUSI, 2026.

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