By Paul Kallender-umezu
TOKYO — Japan’s response to Chinese anti-access/area-denial threats rest on three planks: increasingly large helicopter carriers, next-generation 3,300-ton Soryu-class submarines and new Aegis destroyers.
When integrated, this will create a much more capable fleet able to expand its role beyond being a simple “shield” to the US Navy’s “spear,” analysts said.
Data from AMI International shows that the Izumo-class helicopter destroyers (22DDH) and the Soryu-class submarines are the leading programs for the Japan Maritime Self-Defense Force (JMSDF), both in budget and importance to Japan’s maritime security, according to Bob Nugent, affiliate consultant at AMI.
The Soryu-class boats are larger than any previous Japanese submarines since the WWII
Japan unveiled the first of the two planned Izumo-class ships on Aug. 6, 2013 — the largest Japanese warship since World War II — which will be able to carry 15 helicopters. In 2009 and 2011, the Navy also commissioned two new third-generation Hyuga-class helicopter destroyers, each capable of deploying 11 helicopters. Nugent said that at almost 20,000 tons full-load displacement, compared to the Hyuga class at 13,950 tons, the 22DDH are not fully aircraft carriers because they cannot launch, recover and sustain fixed-wing aircraft, meaning they are still helicopter-carrying “destroyers.”
Still, they comprise a key step in the JMSDF’s evolution into a force with significant seagoing aviation platforms and capability.
“The Izumo class are really fleet flagships with advanced command and control, as well as advanced ASW [anti-submarine warfare] and anti-mine warfare capabilities,” he said.
The Soryu-class submarines made headlines in June when Australia and Japan agreed to jointly develop a range of submarine technologies, with a view to possibly purchasing the highly advanced, stealthy submarines. In September, the JMSDF announced it would further improve the submarine’s capabilities with new battery technologies. The Navy operates five of the attack subs and 11 older Oyashio-class vessels.
It plans a total fleet of 22 submarines.
“The Soryus are among the largest and most successful conventionally powered submarines being built and operated in the world today. And with the latest reporting that Japan is looking at shifting out of fuel cell AIP [air independent propulsion] for the secondary propulsion, the Soryu class is also significant as a global bellwether on technology and design of future conventional submarines,” Nugent said.
“It’s probably true that JMSDF is transitioning to Lithium ion batteries, but perhaps not until a new class of submarines,” said Paul Giarra, president of Global Strategies & Transformation, a professional services consultancy.
“It’s also probable that there won’t be a removal of the AIP package, it seems that doing so would be a step backwards. A key issue to watch will be whether new Li-ion batteries that are safe will make their way into naval applications.”
The third major JMSDF program, its Aegis-equipped cruisers, is moving to the center of Japan-US defense procurement cooperation, especially now that Japan has committed to two new Atago-class Aegis destroyers, with the goal of expanding Japan’s Aegis fleet to eight ships by the end of fiscal 2020.
“They are also important signals to the region of each country’s commitment to operating the best possible sea-based capability for air and missile defense,” Nugent said.
The new mix of capabilities goes beyond platforms and capabilities, with many of the critical changes involving the integration of systems and strengthening of joint functions, said Alessio Patalano, a naval expert at the Department of War Studies, King’s College London.
Of the three programs, Patalano said the next-generation Soryu-class subs will probably make the biggest contribution to Japan’s deterrence posture.
“The geographic characteristics of the main maritime theaters of operations favor submarine warfare. One of the key questions for the Japanese is how to increase the operational range and endurance of their boats so that they can operate longer at sea, and — if necessary — further from Japanese shores,” Patalano said.
“I would say the Soryus are the most important from a strictly national security point of view. I don’t see how you have a plausible ASW capability without submarines,” said Corey Wallace, a Japan security policy expert at New Zealand’s University of Auckland.
Wallace argued that while it is true that more capital outlay has gone toward purchasing new destroyers while submarines have undergone life extensions, this builds on a backbone of 30-plus years of JMSDF investment in submarines and then learning how to use them for ASW, he said.
“In terms of widening the range of the Soryu, I think the first priority is to allow them to stay at sea and submerged longer, rather than necessarily actually going great distances away from the Japanese home islands in a straight line. Still, the ability to project power into the South China Sea in the future is something that the JMSDF probably imagines will contribute to regional deterrence overall,” Wallace said.
The increasing capabilities of the carrier force and ballistic missile defense (BMD) destroyers pose additional questions: Is Japan moving toward creating infrastructure for its first aircraft carrier battle group, and why does the JMSDF need two more missile cruisers?
The Izumo and Hyuga classes are already becoming increasingly important as command-and-control platforms around which the fleet is organized, and also for responses to natural disasters that will bolster the JMSDF’s visibility — but that is part of the problem.
The JMSDF has focused on its submarine buildup specifically because they are more out of sight and less expensive than large surface warships. Before considering the risk of accelerating China’s military buildup and possibly moving the region to a full-blown arms race, developing a carrier fleet would also require Japan to boost its defense spending beyond the psychological barrier of 1 percent of GDP