Is China seeking a submarine presence in the Sea of Japan?

TOKYO — A new security risk may face Japan: China maintaining a constant military presence in the Sea of Japan, a possible launching point for nuclear weapons aimed at the U.S.

Last December, two Chinese H-6 bombers entered the airspace above the Sea of Japan to rendezvous with a pair of Russian Tu-95 bombers. Accompanied by fighter jets, patrol planes and other aircraft from both countries, they flew from the Sea of Japan to the East China Sea.

China has been conducting similar air exercises with the Russian military every year since 2019, as well as naval maneuvering exercises. These add up to a growing Chinese presence in the Sea of Japan.

“It appears the Chinese military wants to eventually deploy Tang-class [Type 096] nuclear ballistic missile submarines equipped with the next-generation JL-3 submarine-launched ballistic missile to the Sea of Japan,” said a former Japanese Defense Ministry intelligence officer.

Such speculation is not new, but it has fast gained currency, triggered by the formation of AUKUS, the trilateral security partnership among Australia, the U.K. and the U.S.

AUKUS’s biggest aim is to contain China’s submarines in the South China Sea with attack submarines, along with large numbers of uncrewed underwater vehicles armed with sensors and weapons.

The South China Sea is relatively shallow. Moreover, a long distance separates Hainan — the Chinese island that serves as the base for China’s South China Sea subs — from where Jin-class Type 094 ballistic missile submarines mainly operate.

The Chinese military has created clusters of artificial islands around reefs in the South China Sea. The islands are part of China’s efforts to ensure the survival of its Jin-class nuclear subs armed with the JL-2 missile, its most powerful SLBM threat to the U.S.

But AUKUS has adopted a “transparent sea” initiative that seeks to improve undersea surveillance capabilities using advanced technology. These advances could make the South China Sea less safe for Chinese subs.

To escape this fate, China needs to move ballistic missile submarines to more secure waters, with the Sea of Japan a leading candidate. An SLBM launched from the Sea of Japan would have a shorter distance to travel to the U.S. over the Arctic Circle, giving Washington less time to respond.

U.S. President Joe Biden, Australian Prime Minister Anthony Albanese and British Prime Minister Rishi Sunak deliver remarks at an AUKUS meeting in San Diego, U.S., last year.   © Reuters

“If a crisis occurs on the Korean peninsula in the distant future, the Chinese military could take advantage of the turmoil by occupying the northern part of North Korea and create a corridor extending from northeast China to the Sea of Japan,” said the former Defense Ministry intelligence officer.

“If the Chinese military were to secure Rason port, which the Japanese military also used during the [Pacific] war, then the Chinese could use the location as the home port for SLBM units, and the waters nearby Rason are deep enough to conceal SLBMs,” this person added.

The repeated flights of bombers above the Sea of Japan could be considered attempts to establish air readiness to protect SLBMs.

North Korea has maintained a policy of not allowing Chinese warships to dock at Rason, or at any port along the eastern seaboard, perhaps out of wariness toward China’s intentions.

But it is not unimaginable that North Korea may someday give China access to land near the northern border, in return for China’s and Russia’s backing during an invasion of South Korea. If that were to happen while the U.S. is distracted by conflicts in Eastern Europe and the Mideast, there is a non-zero chance that Pyongyang could take control of all of South Korea, or the northern part of it.

This scenario is consistent with North Korea’s heightened hostilities against South Korea in recent months.

Under President Xi Jinping, China has made no secret of its goal of unifying with Taiwan. For those ambitions to become a reality, China would need to prevent intervention by the U.S., according to the former intelligence officer.

For China to be in a position to thwart the U.S., it would require “conditions in which Chinese SLBM can be preserved for striking the U.S. mainland as a last resort, even after an escalation of a U.S.-China war,”  this person said.

A Chinese navy submarine takes part in a naval parade off the eastern port city of Qingdao in 2019.   © Reuters

The Chinese military would need to deploy ballistic missile submarines to the Sea of Japan to attain that readiness, which would open up the possibility that Chinese forces would expand into the Sea of Japan prior to a crisis breaking out in Taiwan.

If the Chinese forces including the SLBM units were to take the unprecedented step of maintaining a regular presence in the Sea of Japan, Tokyo would be forced to reassess its own security readiness.

Since the Cold War, the Japan Self-Defense Forces have been prepared to cooperate with the U.S. military to respond to Soviet or later Russian ballistic missile submarines stationed in the Sea of Okhotsk. In future, if Chinese ballistic missile submarines are essentially driven out of the South China Sea by AUKUS, Japanese forces would need to confront them in the Sea of Japan.

Not only would Japanese forces need to improve anti-sub capabilities, they would also have to deepen their collaboration with the three AUKUS militaries.

Last June, China regained the right to use Russia’s far eastern port of Vladivostok for the first time in 165 years. China is known for having maritime militias board civilian vessels. There is a real possibility that China will step up its military intelligence-gathering operations with Chinese commercial ships passing through the Sea of Japan.

Meanwhile, Japanese and Australian defense ministries officially agreed last month to launch a joint research project geared toward the interoperability of undersea drones deployed by both nations.