Japan's submarine fleet can grow to 30 subs, making Japan a linchpin of Pacific undersea security
While America’s nuclear submarine fleet is incomparable, the United States is not the only nation with advanced undersea warfare capabilities. During the Cold War, NATO’s ability to counter the Soviet Union’s formidable submarine fleet benefited from the contributions of submarines operated by the United Kingdom and other NATO allies. In coming years, something similar is going to be true in the Pacific, where an expansionist China has been working steadily to create a large and modern submarine force to contest U.S. and allied control of the critical underwater domain.
As the United States and allies in the Pacific begin building the collaborative framework required to maintain their shared edge in undersea warfare over China, America’s submarine fleet will soon begin an unavoidable decline in numbers. The U.S. Navy’s front-line Cold War-era Los Angeles-class submarines are aging out, and America’s fleet of 52 nuclear attack submarines will soon begin to dwindle down to a minimum of about 42 boats in 2027-2028 before the force begins to once again grow in size.
The coming shrinkage of the U.S. Navy’s submarine fleet is not news—the Congressional Research Service has warned about it each year since 1995. To mitigate the decline, the U.S. Navy is now building new Virginia-class attack submarines as fast as it can, and it also plans to refuel and extend the service lives of several Los Angeles-class boats. But at this point, these and other measures can only do so much. The decline in the force will still occur: As Ronald O’Rourke, a renowned naval analyst for the Congressional Research Service, says, this reduction in force is now “baked into the cake.”
By itself, this decline in submarine numbers could create a roughly decade-long situation of weakened conventional deterrence against China. Chinese strategists are aware of the coming decline and have mentioned it in at least one of their own naval journals. But the decline also offers an opportunity for prepared U.S. allies and partners to take up the slack by temporarily increasing their own undersea warfare capabilities. With the start of the decline now almost upon us, it has become increasingly clear that an important option will be for like-minded Pacific nations to help fill the gap and, in the process, become more equitable partners in advancing Pacific security against an expansionist China.
It is a real opportunity for the right naval force.
The remaining part of the shortfall offers Asian nations their biggest opportunity in decades to align themselves with America’s technical undersea prowess, potentially leveraging American knowledge, skills and resources, just as the United Kingdom did during the Cold War. By offering more of their own submarines to operate in conjunction with the U.S. Navy’s undersea fleet, Japan can not only compensate for the decline in U.S. submarine numbers, but also set the stage for a wider Japanese role in regional collaborative security efforts in coming years.
Demonstrating a deep commitment to a peaceful and prosperous Pacific, governed by the rule of law, is a role that Japan, in particular, is in a position to play, and the oft-underestimated O’Rourke has already done the legwork, identifying Japan’s opportunity to help overcome America’s looming shortfall in undersea platforms.
The Japanese sub fleet is a daunting force
Japan To The Rescue!
O’Rourke’s observations failed to garner much public notice, coming in early June, at the end of a two-and-a-half-hour House Armed Services Committee hearing. But O’Rourke took a few final minutes of the hearing to focus upon Japan’s potential to field a far larger submarine fleet, noting, “I have tried to scour the world for unrealized Western naval force structure, and the number one opportunity I have identified is the Japanese attack submarine force.”
Japan builds one attack submarine a year, and with a 22-submarine force-size goal, Japan simply retires each submarine after 22 years of service. As O’Rourke mentioned, if Japan “were to simply to make a decision to keep their submarines in service for 30 years—more like our own service—they could grow their submarine force from 22 to 30 without building a single boat more than what they already plan to build.”
The timing could not be better. Should Japan recalibrate from their current 22-submarine goal to 30 boats right away, O’Rourke continued, “They would hit 30 within a year of when we are at the minimum of our own attack submarine valley.” Growing the Japanese sub fleet by eight would make a notable contribution toward offsetting the decline in U.S. submarines and strengthen Japan’s contribution to allied security in the Indo-Pacific.
Japan's naval forces are daunting, but their sub fleet is the strategic "glue" for the region
Japan’s Quiet Competence:
This relatively painless effort to grow the Japanese submarine fleet to 30 boats offers Japan a chance to achieve an enormous boost to the country’s international standing. Rational American defense leaders are already pondering a closer relationship, and at the House Armed Services Committee hearing, retired Chief of Naval Operations Admiral Gary Roughead echoed O’Rourke, saying, “It’s time that we change the nature of our alliance with Japan,” and, “they have really good stuff and they’re very, very proficient operators.”
In the undersea domain, Japan’s submarine force is deeply respected throughout Asia, and even America’s anti-submarine warfare operators can struggle to track Japan’s modern fleet of super-quiet non-nuclear submarines. Capitalizing on this competence by expanding Japan’s submarine force would send a far better message to the region than the constant hand-wringing by those who are all too eager to paint the U.S. Navy as a spent and broken force.
Certainly, Japan may need to tweak their operational procedures and maintenance strategies to keep submarines in service for 30 years and grow their sub fleet by almost 40 percent. But Japan should have few problems finding the extra six hundred or so sailors (plus some extra shore support personnel) needed to put eight more submarines into the field. Japan already maintains two training boats, and, as a maritime-minded country that meticulously tends to personnel training and vessel maintenance, finding the sailors to support this prestigious opportunity for Japan to demonstrate its commitment to a free and open Pacific is eminently possible. And a hard-pressed U.S. Navy should welcome any additional Japanese submarines, particularly if deeper U.S.-Japanese cooperation in the undersea domain leads to a greater Japanese appreciation for the joint mindset that will be required in coming years to effectively counter China’s improving naval capabilities.
