The independent resource on global security

Tensions in the South China Sea: the nuclear dimension

Ever since China started constructing artificial islands in the South China Sea (SCS) on an unprecedented scale and speed by the standards of the region, the world’s attention has turned again to the intricate sovereignty disputes involving China, Taiwan, the Philippines, Vietnam, Malaysia and Brunei. Many expert comments and opinion pieces have explained Chinese actions in terms of sovereignty claims. This piece sheds light on a specific strategic interest pursued by China in the South China Sea: the People’s Liberation Army’s (PLA) quest for a credible undersea nuclear deterrent. This dimension is easily overlooked, as the PLA has never officially mentioned the strategic importance of the SCS for China’s future nuclear posture. However, several signs suggest that the PLA’s nuclear deterrence strategy provides an important context to understand land reclamation work in the SCS.

The construction of a ballistic missile nuclear submarine force has been a priority of the PLA since Mao Zedong identified SSBNs as a key procurement goal to support China’s security and independence. Mao famously said in 1959: 'We need to build a nuclear submarine, even if it takes us 10,000 years'. However after six decades of effort, the Chinese arms industry has yet to produce a reliable undersea nuclear deterrent. Today, at least four SSBNs are in service in the PLA Navy (PLAN). China tested its first submarine-launched ballistic missile (SLBM)—the JL-1—as early as 1988. However, there is no compelling evidence that the PLAN’s current nuclear submarine force guarantees a reliable second-strike capability to China. Several test-flights of the JL-2 have been conducted but it remains unclear as to when the missile will become operational. Many questions also remain regarding the capacities of the new class of SSBNs in service with the PLAN. In particular, propulsion problems remain a tremendous obstacle. Moreover, the fact that the Chinese arms industry is focusing on the next generation of SSBNs and SLBMs confirms that achieving an undersea second-strike capability is still a work in progress.

The SCS already plays an important role in China’s submarine strategy. In 2014, photos revealed three Chinese SSBNs stationed in the new Yulin Navy base on Hainan Island. Given the extreme difficulty of crossing the first island chain undetected to operate in the deep waters of the Pacific Ocean, providing deterrence from the SCS is a rational option. The Chinese SSBNs would have to be able to leave the underground facilities of the Yulin base undetected and remain protected from anti-submarine warfare (ASW) activities conducted from the air, the sea, the undersea and outerspace. From China’s perspective, this is an enormous challenge given the current balance of military power in US-China relations. It implies achieving air and sea superiority, evading monitoring from intelligence satellites and denying access to nuclear attack submarines.

In this context, it is likely that US surveillance operations—framed as enforcement of freedom of navigation in the SCS—are also perceived in China as a strategy to deny the PLA a reliable second-strike capability. In recent years, the PLA has described intelligence gathering as a priority security concern. The PLA’s most recent guideline to describe its military diplomacy towards the US, the ‘new type of great power military-to-military relations’ (which is a variation on Xi Jinping’s ‘new type of great power relations’), comes with ‘three obstacles’, one of them being surveillance of China’s naval activities.

Indeed, the PLAN is under constant US surveillance and Chinese nuclear submarines are a particular priority. In June this year, Chen Xiaogong, a former deputy commander of the PLA Air Force, noted that the US military carried out 1,200 reconnaissance flights over waters close to China in 2014. A further factor is the current trend in Asia towards regional integration of intelligence, surveillance and reconnaissance (ISR) activities under US leadership. In just a few months, many significant developments have occurred. In February, the US Navy started to deploy its most advanced ASW and surveillance aircraft, the P-8A, at the Clark Air base in the Philippines. The P8-A is planned to gradually replace the P3C Orion, still the most widely used ASW aircraft among US friends and allies in the region. In April, the Taiwanese Navy announced for the first time its intention to dispatch the P-3C Orion on surveillance missions in the SCS. At the same time, Japan and Vietnam are moving fast to enhance their ASW and ISR capabilities, while the Philippines is building its own surveillance capability with the help of Japan and the USA.

Thus, the main problem of the Chinese nuclear submarines, noise, is aggravated by constant surveillance operations with an ASW component. These conditions pose a major obstacle to the undetected functioning of SSBNs, which appears to be possible only with reliable area protection. It seems likely that in order to protect its SSBNs China may have chosen to provide area cover for submarine operations on a soviet model (‘Bastion strategy’). It is perceived that this strategy can be achieved with the development of proper Chinese surveillance capabilities, attack submarines and aircraft—including on aircraft carriers—to provide air cover. While Chinese strategists only exceptionally use the notion of ‘bastion’ in the context of the SCS, several areas (especially in the northern parts of the SCS) could be used to conceal submarines if sufficient air cover and ASW capabilities are deployed.

It is worth noting that China’s artificial islands may have a role to play in support of such a scenario. At the Xiangshan Forum in Beijing in November 2014, a senior PLA Air Force officer explained land reclamation in the context of the ‘need for a base to support our radar system and intelligence-gathering activities’. According to satellite imagery released in April and May, there is artillery deployed on at least one island. Photos also show radar and communication equipment, and that construction of harbours and runways are ongoing. Clearly all these facilities will be useful for extending the range of China’s air defence and maritime domain awareness. The facilities would also make US surveillance activities more complicated, even though they would be highly vulnerable in the worst-case scenario of a military conflict.

The undersea component is considered to be the most reliable part of a strategic arsenal, as these nuclear weapon carriers are the hardest to detect. The logic of surveillance versus counter-surveillance has an obvious conventional dimension: at stake is the balance of power between China and the other claimants in the SCS. However, Chinese military activities in the SCS are likely to be determined in part by the vulnerability of its nuclear submarines. Excluding this possibility would risk missing a key feature of China’s threat perception and national security policy. Thus, tensions in the SCS should be seen through a wider lens than just a buildup of conventional weaponry, and any de-escalation may require a nuclear arms control component. In any case, understanding to what extent nuclear security shapes China’s policy in the SCS requires further research and dialogue.