The New Nuclear Submarine at Bohai Shipyard Highlights Structural Challenges in Japan's ASW Operations

On February 9, images captured by the Sentinel-2 satellite indicate that China's defense industry has entered a new phase. The silhouette of a vessel over 110 meters in length floating in the Bohai Shipyard's launch dock—this is the first ship of the People's Liberation Army Navy's third-generation attack nuclear submarine, Type 095 (NATO reporting name: Sui class).

What I find noteworthy is not so much the technical details of this vessel, but rather the fundamental questions it poses to Japan's maritime defense posture.

The Leap in Quietness Signified by the X-Type Tail

According to an analysis by Naval News, the Type 095 is the first Chinese nuclear submarine to adopt an X-type tail. This design follows a similar approach to the U.S. Navy's Virginia-class attack submarines and offers the following advantages over traditional cruciform rudders:

• Improved steering efficiency and enhanced maneuverability in shallow waters
• Reduced acoustic signature through optimized placement of control surfaces
• Increased quietness when combined with pump-jet propulsion

With a displacement of 9,000 to 10,000 tons, the scale has significantly expanded from the 7,000-ton class 093 series. Reports from TheDefenseWatch suggest that much of this increase is allocated to enhancing quietness and incorporating electronic warfare systems.

The question is how well the Japan Maritime Self-Defense Force's current ASW (anti-submarine warfare) capabilities can cope with the quietness of this generation.

Limitations of the P-1 Patrol Aircraft and SOSUS

The JMSDF has deployed 70 Kawasaki P-1 patrol aircraft, establishing a surveillance network from the East China Sea to the Japan Sea. However, the magnetic anomaly detection (MAD) system on the P-1 has limited detection range, and acoustic detection using sonobuoys is heavily influenced by the target submarine's quietness.

The underwater acoustic monitoring system (SOSUS), operated jointly with the U.S. military, is also designed based on Cold War-era Soviet submarines. If the Type 095 truly achieves quietness comparable to the Virginia class, as assessed by the U.S., the traditional surveillance network may struggle to keep up with updates to the "acoustic signature library."

Even more concerning is the fact that since 2022, the Bohai Shipyard has been launching 2 to 3 nuclear submarines annually. Following the mass production of the 093B class, if the Type 095 enters full-scale production, the targets the JMSDF must monitor will increase dramatically in both quality and quantity.

Blind Spots in Maritime Traffic Route Defense

From my experience during my time in the JMSDF, Japan's anti-submarine warfare concept has focused on "choke point defense." The basic idea is to intercept enemy submarines in narrow waterways such as the Miyako Strait, Tsushima Strait, and Tsugaru Strait, preventing their advance into the open sea.

However, with the improved range and quietness of the Type 095, scenarios where it bypasses the outer edges of the East China Sea and the Japan Sea to directly deploy in the Pacific SLOC (Sea Lines of Communication) become more plausible. In such cases, the JMSDF's submarine fleet (22 vessels combined from the Soryu and Taigei classes) alone would not be able to cover the vast maritime area.

The underwater unmanned vehicles (UUVs) that the Ministry of Defense plans to introduce starting in fiscal year 2024 are a partial answer to this challenge, but establishing an operational framework will take several years. During this gap, China will likely exploit the situation.

Structural Contradictions in Budget Allocation

It is important to point out the issue of prioritization in Japan's defense budget.

Under the Takai administration, defense spending has been increased to over 2% of GDP, but the majority of this has been allocated to the deployment of the Ground Self-Defense Force in the southwestern islands, additional procurement of F-35s for the Air Self-Defense Force, and the development of counterstrike capabilities (so-called long-range missiles). Budget allocations related to anti-submarine warfare—development of a successor to the P-1, enhancement of sonobuoys, and mass production of UUVs—have been relatively deprioritized.

A colleague at the Defense Research Institute wryly remarked, "Even if the Type 095 is deployed in the East China Sea, it doesn't directly attack the Senkaku Islands. Therefore, politically, it has a lower priority."

The Overlooked Essence

TheDefenseWatch points out that the emergence of the Type 095 will "accelerate the submarine development competition among regional countries." Indeed, Australia is acquiring Virginia-class submarines under the AUKUS agreement. South Korea is also considering its own nuclear submarine program.

But what about Japan?

Due to constitutional interpretations and the constraints of the Three Non-Nuclear Principles, possessing nuclear-powered submarines is politically difficult. Therefore, we have no choice but to counter with improvements in the performance of conventional submarines and ASW aircraft and vessels. Nevertheless, it is hard to say that sufficient budget and technological development are being allocated for this purpose.

What concerns me most is not the performance of the Type 095 itself. The real issue lies in the structural blind spot where Japan's defense policy overreacts to "visible threats" while overlooking the qualitative superiority of underwater combat capabilities, which are "invisible threats."

The satellite images from February 9 revealed not just the launch of a new type of vessel, but a quiet crisis facing Japan's maritime defense strategy.