Home inFocus Defense: Rising Challenges and Changing Strategies (Fall 2020) Why Japan Must Reconsider Its Aegis Deployments

Why Japan Must Reconsider Its Aegis Deployments

Daniel Goure Fall 2020

The security environment in the Western Pacific is becoming more challenging for the U.S., its friends, and allies. China seeks to dominate the region and project power globally. North Korea is expanding its arsenal of ballistic missiles and nuclear warheads. To successfully deter Beijing and Pyongyang, and counter their ability to use military coercion, the U.S. is improving its defense posture in the region both qualitatively and quantitatively. U.S. allies in the region, chief among them Japan, need to do the same. But will Japan make the appropriate investments?

The balance of powers in the Western Pacific is changing rapidly. China is seeking to build a “great power” military that could outmatch that of the U.S.   It is investing in a wide range of high-tech capabilities. Many of these are designed explicitly to counter areas of U.S. advantage or exploit clear vulnerabilities. In a recent report to Congress, the U.S.-China Economic and Security Review Commission identified a number of specific capabilities the Peoples Liberation Army  (PLA)is developing for the purposes of targeting U.S. military forces and countering its advanced capabilities.

An Aegis SM-3 Block 1B interceptor launched from the USS Lake Erie during a interception test off the coast of Kauai, Hawaii. (Photo: U.S. Missile Defense Agency)

The weapons and systems under development and those that are being fielded by China’s military—such as intermediate-range ballistic missiles, bombers with long-range precision strike capabilities, and guided missile nuclear attack submarines—are intended to provide China the capability to strike targets further from shore, such as Guam, and potentially complicate U.S. responses to crises involving China in the Indo-Pacific.

China’s increasingly accurate and advanced missile forces are intended to erode the ability of the United States to operate freely in the region in the event of a conflict and be capable of holding U.S. forces in the region at risk. 

China’s continued focus on developing counter space capabilities indicates Beijing seeks to hold U.S. intelligence, surveillance, and reconnaissance satellites at risk in the event of conflict. 

In particular, the PLA is rapidly expanding its capabilities to conduct massed, long-range strikes against both fixed facilities and mobile forces. The PLA Air Force is now operating its own version of a fifth-generation stealth fighter and will soon introduce a new long-range strategic bomber.  The PLA has deployed a large number of long-range precision-guided ballistic and cruise missiles, one of which, the DF-21, is believed to be specifically designed to attack large surface warships such as U.S. aircraft carriers. Conventionally-armed missiles will be employed in massed attacks, intended to cripple opposing forces at the outset of hostilities. The PLA Navy is rapidly expanding with new attack submarines, aircraft carriers, missile destroyers and large amphibious warfare ships.

In response, the U.S. military is making significant changes to its force posture and concepts of operation. The overall goal is to distribute units more widely throughout the region, make each formation and platform more lethal and agile, and enable joint force commanders to employ capabilities across all the warfare domains. The Marine Corps’ concept for Expeditionary Advanced Base Operations, which focuses on smaller, agile formations that are constantly moving in proximity to hostile forces while conducting long-range fires, exemplifies the change in how the U.S. plans to conduct future high-end warfare.  

The U.S. military is investing in new and expanded capabilities to support these forces. One of the most important areas for modernization is in long-range, precision strike systems such as the Long-Range Air-to-Surface Missile, the Tomahawk cruise missile Block V, and the Army’s Precision Strike Missile. Another area is missile defense, using land-based systems such as Aegis Ashore and the Terminal High Altitude Area Defense System, and the sea-based Aegis Ballistic Missile Defense System with the new SPY-6 radar.

U.S. allies share Washington’s view on the growing security threat posed by China. In response, they are increasing defense expenditures and spending more on modernization. A major initiative in this is the acquisition of the F-35 Joint Strike Fighter by Japan, Australia, and South Korea.

It is impossible to overestimate the importance of Japan as a U.S. ally. Japan plays a unique role in the security of the Indo-Pacific region due to its location, economic power, and close ties to the United States. The U.S. bases Air Force, Navy and Marine Corps forces in Japan precisely because of its unique geographic position.  Thus, it is highly likely, really a virtual certainty, that Japan will be involved in any conflict between the United States and China.

The government of outgoing Prime Minister Shinzo Abe made deterrence of the Chinese and North Korean threats its number one security priority.  To that end, it is pursuing a national security strategy that focuses on improving the Japanese Self Defense Forces (JSDF) both qualitatively and quantitatively. The JSDF also has begun creating cyber security units as well as developing the capability to conduct multi-domain operations as the U.S. plans to do. 

In recent years, Tokyo has undertaken a significant program of military modernization designed not only to improve its ability to defend the homeland and surrounding waters, but also to project military power to more distant regions. In addition to committing to purchase some 147 F-35s, Japan has acquired or plans to buy V-22 tilt-rotor transport aircraft, P-8 anti-submarine warfare planes, KC-46A aerial refueling tankers, AH-64 Apache gunships, E-2D Advanced Hawkeye airborne early warning aircraft, and Patriot air defense systems from the U.S. Most of the country’s fleet of F-15Js will be upgraded with new electronics and the ability to carry advanced weapons. 

In addition, Japan is investing in indigenously-produced capabilities, intended to expand the reach and flexibility of its military forces. The JSDF has modified two Izumi class destroyers into mini-aircraft carriers capable of handling the short-takeoff/vertical landing F-35B.  The country has begun an R&D program for a sixth-generation fighter to replace its aging F-1s. Tokyo participated in the successful co-development program with the United States for an advanced variant of the Standard Missile 3 (SM-3), designated the Block IIA, for the anti-ballistic missile mission.  Both countries are now deploying this new missile killer. Japan also will collaborate with the United States on developing and deploying an array of small, low-orbiting missile warning satellites. 

The end of the Abe era is a time to consider Japan’s future role in the security architecture of the Indo-Pacific region. Frankly, Japan needs to do more if it is to have any hope of deterring China and North Korea. It must build on the efforts of the past decade. In essence, Japan needs to be able to deflect and degrade any initial Chinese or North Korean attack, providing time for the U.S. and other allies to respond militarily. With the proper additional investments in offensive and defensive capabilities, it could be an “unsinkable aircraft carrier,” the role played by many Pacific island bases and even Great Britain during much of WWII. 

This means, in part, investing seriously in active and passive defenses to counter the air and missile threats from China and North Korea. Some observers have gone even farther, proposing Japan adopt a strategy of “active denial” designed to make Japan less vulnerable to attack by expanding both its defensive capabilities and simultaneously increasing its capability to attrit hostile offensive forces even at long distances from the Home Islands. 

One area that has become problematic is missile defense of the homeland. In the event of a conflict with China, most experts believe that the PLA will attempt to employ its vast arsenal of conventionally-armed ballistic and cruise missiles to destroy both U.S. and JSDF targets in Japan. It is critical that Tokyo takes steps to counter this threat thereby and make clear to Beijing that it cannot count on achieving a swift, disarming strike at the outset of hostilities. 

Japan had begun a program that would have provided it with the basis for a credible defense against the growing Chinese missile threat. It invested in the Patriot terminal air defense system and acquired eight destroyers equipped with the Aegis Ballistic Missile Defense System including advanced variants of the Standard Missile. 

In addition, several years ago, the Abe government decided to acquire two Aegis Ashore missile defense systems. This is the same system currently deployed in Europe. One reason Japan decided to acquire the Aegis Ashore was to reduce the burden on its destroyer fleet associated with serving as that country’s primary missile defense capability. A missile defense based entirely on sea-based capabilities is not always optimally located to protect land areas. In addition, destroyers assigned the missile defense mission for the Japanese homeland are generally restricted to a small ocean area, close to land. As a result, ships on missile defense patrols are unavailable for other critical missions.

However, a few months ago, the Japanese Ministry of Defense announced it was halting the procurement. According to the Defense Minister, Taro Kono, the suspension decision was based on both technical and cost issues with the program.  The principal technical concern is the danger that from the currently planned sites, the SM-3 Block IIA booster might fall into populated areas.  Modifications will be required to the missile’s software and, possibly, hardware to solve this problem. There was also local opposition to the placement of the AN/SPY radar near populated areas. There are reports that the Japanese government had decided to halt the planned deployment at the site in Akita prefecture in the northwest of Honshu, Japan’s main island and to explore alternative locations. 

With respect to cost, it is true that the price for completing each of the two sites had increased by some 25 percent to around $900 million. However, it should be pointed out that the cost of a single Japanese missile defense-capable destroyer is now approximately $1.5 billion, exclusive of expendables such as the SM-3 Block II missiles. Moreover, the manpower needed to operate additional Aegis-capable destroyers far exceeds that for an equivalent land-based missile defense system. For defense of the Japanese homeland, a shore-based system is the cost-effective solution.

Japan is now searching for an alternative approach to defending itself against the PLA’s missile threat. Consideration is being given to adding a couple of additional Aegis-capable destroyers and even massive, offshore missile defense platforms. 

The Japanese government needs to rethink its decision to halt work on the Aegis Ashore program. In light of the growing missile threats posed by China and North Korea, Japan needs to field a multi-layer missile defense. Such a defense is essential to maintaining a credible deterrent. In addition, in the case of North Korea, it is a hedge against a potential accidental or unauthorized launch. The chief of staff of the Japanese Maritime Self Defense Forces publicly challenged the decision to cancel Aegis Ashore, arguing that only a land-based system can provide year-round, continuous, all-weather missile defense.  Eight or even 10 Aegis-capable destroyers are simply not sufficient to manage the threat. The most sensible, and cost-effective solution is to move forward with Aegis Ashore deployments, modified as necessary to meet credible concerns.

But an improved defensive posture may not be sufficient to deter China. A credible deterrent requires that Japan be able to strike critical PLA military targets, including those that might be aim at Japan. During World War II, Great Britain relied on Bomber Command to be the offensive complement to its home defense capabilities. Japanese sources have raised the possibility of developing “enemy base attack” capabilities as part of its deterrent strategy. In the event of a conflict with China or even North Korea, those countries’ military facilities, ISR capabilities, command centers and forces cannot be granted immunity from attack.

The United States military is looking at new strategies, forces, and equipment with which to counter the Chinese military’s growing power in the Western Pacific. Japan must be part of the solution. But in order to play the role of an unsinkable aircraft carrier, Japan must invest more in advanced offensive and defensive capabilities. 

Daniel Gouré, Ph.D., is a vice president at the public-policy research think tank Lexington Institute.