Missile Deployments Only the Tip of the Iceberg

The news that China has deployed bombers and cruise missiles to contested reefs and islands in the South China Sea has caused significant concern. The move allows Beijing to target ships in disputed waters with a missile capable of manoeuvring around defence systems at Mach 3. It has also placed northern Australia within reach of Chinese warplanes.

Beijing, for example, has used fishermen, armed paramilitary vessels, media, and psychological and legal tactics to the same effect as missiles and planes. It’s also advancing in another domain that is comparatively less discussed—underwater.

The opaqueness of water is perfectly suited to ‘hybrid’ strategies that use plausible deniability as a modus operandi. So what might Beijing’s hybrid strategy look like under the waves?

The People’s Liberation Army is busy expanding its undersea toolbox. It has developed autonomous undersea gliders that can dive six kilometres deep to undertake sonar countermeasures, track surface and subsurface targets, or create a surveillance network that may enable over-the-horizon torpedo launches. In addition, it’s rumoured to be building an ‘underwater Great Wall’ of seabed sensors that feed into fibre-optic cable stations on the same reefs housing the latest missiles.

Other states’ capabilities also indicate platforms that Beijing may possess. Russia’s Main Directorate of Deep Sea Research, for example, operates at least two vessels—the surface ship Yantar and a converted ballistic missile submarine—believed to be equipped with unmanned underwater vehicles (UUV)s that can manipulate objects on the ocean floor. It’s not unreasonable to assume that the PLA is developing capabilities similar to those of the Yantar or even of the USS Jimmy Carter, which is rumoured to be able to tap undersea cables and deploy UUVs, although little open-source evidence is available.

This pattern of investment suggests three strategic goals. First, the PLA is advancing its ability to monitor vessels passing through contested waters. If reports of the underwater Great Wall are reasonably accurate, then the system would give Beijing unrivalled information about submarine and surface vessel movements in the South China Sea. Like air defence identification zones, the system strengthens Beijing’s de facto control over its maritime claims—a key component of the idea that legitimacy is granted by facts, known as doctrinal unilateralism. Beijing may be hoping that if it controls a contested area for long enough, its claims will eventually gain legitimacy.

Second, Beijing is seeking to raise the costs of foreign intervention in a conflict in the South China Sea, particularly over Taiwan. Chinese strategists will have noted that one reason Russia continues to occupy Crimea is that, as far as Washington is concerned, the costs of re-taking the peninsula are greater than its strategic value. The PLA is investing in underwater assets, alongside other anti-access and area denial capabilities, in the hope that Taiwan falls victim to the same strategic equation. Some argue that it already has. This would facilitate other hybrid tactics, such as incursions by fishing vessels in radio contact with armed coast guard ships.

Third, it’s possible that Beijing is seeking new ways of intimidating or spying on other states. The ocean bed is crisscrossed by telecommunications cables that carry 98% of global internet and phone data and 95% of American strategic communications. The cables are vulnerable: most are roughly the width of a soda can and covered in a thin rubber coat, and they’re not protected under Law of the Sea conventions. If Beijing has UUVs that can find and manipulate seafloor objects, it could tap into or sever Taiwanese cables in order to exert economic pressure, create a contested information environment (as Russia did in Crimea) or even prevent foreign drones from operating over the South China Sea.

There are still plenty of questions. It’s unclear how China’s remote undersea sensors and gliders communicate with one another given the strict limitations that water places on data transmission. The U.S. is also investing in underwater capabilities that might negate the strategic advantage that China’s platforms offer. Yet an opaque environment facilitates an opaque strategy—the missiles and planes deployed to contested reefs are only the tip of the iceberg.