Quiet plan to PATROL South China Sea with nuclear subs

China has been accelerating land reclamation on reefs around the Spratly Islands in the South China Sea, heightening tensions with neighbouring countries and the United States.

China has been expanding its effective control of the disputed islands by constructing artificial islands and establishing a military base. 

What changes will these moves by China bring to the security environment around Japan?

China began reclamation work around January last year, after gaining effective control of seven reefs around the Spratlys.

The largest-scale artificial island is on Fiery Cross Reef, where a 3,000-metre-class runway is being built, with the US Defence Department anticipating its completion in 2017 or 2018.

Possessing a 3,000-metre-class runway in the vast South China Sea would be very significant. If operated in combination with port and fuel storage facilities, the runway could serve as an operation and supply base for bombers.

The entire area of the South China Sea could be covered by operating China’s military mainstay Su-30 fighters and H-6 bombers, which have operational ranges of about 1,500 kilometres and 1,800 kilometres respectively. This would make it easier to secure air superiority. 

If the artificial island were to become a base for fighter jets, China would be able to increase pressure on the US military, among others. Fiery Cross Reef, it may be said, is the main stronghold in the “Great Wall of sand”, which consists of several artificial islands.

Concern is mounting in the international community that China will set an air defence identification zone (ADIZ) centering on the artificial island. 

China insists on a territorial claim for a U-shaped area extending from the northern area of the South China Sea. A Japanese Defence Ministry official predicts, “China will establish an ADIZ along the area it claims as its territory and call for the aircraft of other countries to comply with its directives when flying in the ADIZ, as it does in the case of the East China Sea.”

 

Strategic value of location

China attaches more importance to the South China Sea because it is an important sea-lane for China just as it is for Japan. There are also topographical reasons, in addition to its interest in securing natural gas and other resources.

The South China Sea is characterised by its depth. In contrast to the East China Sea, which has a depth of about 200 metres up to the Okinawa trough, the South China Sea has a complicated topographical formation with a maximum depth of about 4,000 metres. This helps enhance “the degree of freedom of action” for submarines, indispensable for offshore military operations when seeking to evade the enemy.

“Submarines on a mission can quickly submerge in deep waters,” said former Vice Admiral Hideaki Kaneda of the Maritime Self-Defense Force, a director at the Okazaki Institute. “Topographical conditions exist in the South China Sea that make it a ‘sanctuary’ [from attacks].”

But there is a disadvantage in deep sea, which is that sound tends to be propagated in a straightforward manner, making submarines easier for the enemy to detect. The US military has been conducting operations to detect Chinese submarines in the South China Sea using patrol planes and through other methods. Because of this, it seems China now aims to secure air superiority over the South China Sea, thereby enhancing its ability to interrupt such activity by US forces.

Security experts believe that China’s “covert purpose” is to be able to advance its nuclear-powered ballistic missile submarines (SSBNs) from the South China Sea into the Pacific Ocean in the future.

At its underground base in Sanya, Hainan Island, China deploys at least two Jin-class nuclear-powered submarines carrying JL-2 ballistic missiles, according to Kaneda. Washington analysis suggests that China will launch patrol activities using these submarines before the end of this year.

The JL-2’s firing range is said to be about 7,000 kilometres at present, so it would be unable to reach the US mainland if fired from the South China Sea. But a Chinese submarine with JL-2 ballistic missiles mobilised in the Central Pacific or the Sea of Okhotsk, or the Bering Sea near the Arctic Circle after passing through the Bashi Channel, would be able to reach targets as distant as the US East Coast.

Yoji Koda, a former commander in chief of the MSDF fleet, said: “China would be able to make nuclear attacks on the US mainland from two or more directions with considerable ease. 

The United States, which cannot allow this to happen, will try to contain Chinese SSBNs within the South China Sea like a ‘birdcage.’ This is how the two countries are confronting each other.”

 

Need for containment

If the South China Sea comes under Chinese control, it will change the military balance in the area dramatically, making it certain to worsen the security environment surrounding Japan.

The new guidelines for Japan-US defence cooperation have incorporated the joint activities of intelligence gathering, surveillance and reconnaissance, with the current South China Sea situation in mind. But concrete measures for implementation remain to be examined.

For the Self-Defence Forces to cooperate in these activities, it is essential to strengthen capabilities in terms of patrol planes and other equipment. The government must explore ways of cooperating within the constraints of security legislation. At the same time, it needs to exert influence on China by strengthening its cooperation with the relevant countries around China.