With China appearing to flex its muscles in almost all of its territorial disputes, a new underwater dimension may emerge. Chinese submarines could be on a collision course with the Japanese Navy. Known as the Japanese Maritime Self-Defense Force (JMSDF), they posses one of the most potent anti-submarine capabilities of any Navy. In particular Japanese submarine technology is highly regarded. But there seems to be acceptance that they will have to beef up to meet the emerging threat from China. A newly published white paper hints at the ways the JMSDF is responding.
The threat of Chinese submarine incursions is seen as very real. Last month the JMSDF scrambled its forces to track a submerged submarine near its waters. It deployed one of its helicopter carriers, two destroyers and several maritime patrol aircraft. Although Japan has not declared the nationality of the submarine, it is widely believed to have been Chinese.
According to the press release (in Japanese) the submarine was detected on June 18 northeast of Amami Oshima, which is one of the islands running between Japan and Taiwan. These islands are known as the first island chain and form a natural barrier between China and the Pacific. The submarine was heading west, out into the Pacific. It was tracked for several days.
China’s bold moves, which also include surface warships and aircraft, are often seen to be connected to its territorial disputes. In its newly released white paper the Japanese Government states that “China has relentlessly continued unilateral attempts to change the status quo by coercion in the sea area around the Senkaku Islands”. The islands are claimed by both countries, but are defacto part of Japan.
The white paper says that Japan will employ its submarines to conduct underwater ISR (Intelligence, surveillance and reconnaissance) in the waters around Japan. This is typically passive language, Japan emphasizes a defensive stance, for monitoring and trailing Chinese submarines and warships near Japan’s territorial waters.
And significantly, Japan has been increasing its submarine force from 16 to 22 boats. While Japan’s submarines are considered very advanced, they will still be massively outnumbered by the Chinese Navy. The white paper says that Japan will maintain “reinforced submarine units” to “engage in patrols and defense in the waters around Japan”.
Japan has already commissioned the world’s first submarine with Lithium-Ion batteries. The improved technology promises to help their submarines stay underwater for longer periods. This will extend endurance even beyond the Air Independent Power (AIP) already used by both japan and China. In the language of the white paper this will allow Japan to create a “persistent ISR posture”.
Incursions into Japanese waters are not new. For example, according to the Japanese Government, in November 2004 a submerged Chinese nuclear powered submarine intruded into Japan’s territorial waters. Japan considered that this was a breach of international law. Full details were not disclosed however. At the time fewer than 10 of China’s submarines were considered modern by Japan. By last year this had increased to 46.
In January 2018 another submerged Chinese Navy submarine entered the contiguous zone around the Miyakojima Island and the Senkaku Islands. The contiguous zone of a country is between 12 and 24 nautical miles of the coast. China did not acknowledge this incident. A Ministry of Foreign Affairs spokesperson answered at the time “I do not have information about the circumstances of submarines.”
The JMSDF’s last Sōryū Class submarine, Tōryū, is expected to be commissioned next year. After that there will be several years lag before the first next generation 29SS class boat joins the fleet. In the meantime China will likely commission its first next-generation Type-095 boat. The hardening stance of the JMSDF will have its work cut out if China increases submarine incursions.