Masashi Murano

This summer, Japan announced it would suspend the deployment of the Aegis Ashore ballistic missile defense system. While Japanese authorities pointed to local concerns about where missile boosters would fall to earth, the decision hinged on a wider array of concerns. It also opened the door to new worries: How would Japan approach missile threats, particularly from North Korea and China?

In the following interview with The Diplomat’s Catherine Putz, Masashi Murano, a Japan Chair Fellow at the Hudson Institute, explains the dynamics of Tokyo’s decision, the country’s existing and potential options for countering missiles, and more.

In June, Japan suspended its planned deployment of the Aegis Ashore ballistic missile defense system. Why did Tokyo make that decision?

It has several reasons for the cancellation of the Aegis Ashore deployment plan.

The Ministry of Defense (MOD) has explained that it made a promise to drop SM-3’s boosters only onto Self-Defense Force (SDF) property, which became unfeasible. This is the official reason for its cancellation.

However, in the first place, it was not appropriate to promise to only drop the boosters onto the SDF sites. This is not so much an issue of the risk of a dropping booster itself, but rather the government was too sensitive to the local public’s zero-risk beliefs. The government had to explain the risks to the locals, carefully persuade them. Even they didn't get complete understanding from locals, the government should have been prepared to take responsibility for national security and make the decision to deploy Aegis Ashore.

Secondly, the booster issue is consequently linked to issues related to program cost overruns from acquisition to operational deployment, which exceeded the original plan. The MOD and the U.S. side had assumed that its software modifications would be enough to allow the boosters to drop safely and controllably onto the SDF property. However, it was discovered that, in fact, it would require not only software, but also a hardware modification of the SM-3, which would require a long period of time and a lot of additional costs.

According to the MOD, this issue was revealed between January and May 2020. But, I don't find this explanation convincing; the SM-3 was originally intended to be used at sea or over large expanses of land, and is not supposed to control dropping boosters. I think it was clear from the beginning that there was no way that the problem could be solved by software modifications alone.

In addition, another reason was due to the selection of a Lockheed Martin SPY-7 radar; the U.S. Missile Defense Agency is responsible for recommending it. The U.S. plans to deploy the same radar in Alaska, but this is a stand-alone radar. The Japanese Aegis Ashore was supposed to be the first SPY-7 radar integrated with the Aegis weapon system. This would have added to the cost of the radar and Aegis system, as well as the test launch costs of expensive interceptors for integration with combat system. It was clear that this would be the case.

The U.S. side initially suggested some benefits of allowing Japanese industries to participate in the manufacture of the radar, but in reality, the U.S. was not able to achieve this. Since this is no longer possible, it has lost its benefit for the Japanese defense industry.

As a result, the original plan to deploy Aegis Ashore by 2025 is not feasible. This is the third reason.

Given the growing seriousness of missile threats from North Korea and China, it is very important to deploy them as soon as possible in order to strengthen Japan’s missile defense posture. I don't see any option to improve Japan’s missile defense posture in the short term other than to revisit where they are deployed and make minor revisions to the original plan for Aegis Ashore.

However, if the original plan is going to be unfeasible anyway, the government probably thought it would be better to just scrap the whole thing now and start reviewing its comprehensive missile-defense policy, including its strike capabilities.

Finally, I would add that the consensus on the operational side was weak. The need for Aegis Ashore to strengthen Japan's missile defense posture is strategic, and there was a consensus at the strategic level. However, there was no consensus at the operational level on who would be in charge of the operation of Aegis Ashore.

The Maritime Self-Defense Force (MSDF), in order to avoid further operational burdens, has been working on the Aegis Ashore program – but they did not want to be actively involved. If the MSDF had been actively involved in the process, the result of the radar selection would have been different. This is because the MSDF would have recommended the introduction of the SPY-6 (not SPY-7), which is used by the U.S. Navy's Aegis destroyers. The Ground Self-Defense Forces (GSDF) was supposed to be in charge of the long-range missile defense mission, which they had never done before.

But given the limited defense resources and the diversity of threats, it is necessary for the SDF to establish joint and integrated air and missile defense posture, and the political decision was correct that the GSDF is in charge of Aegis Ashore.

Can you explain the parameters of the “strike capability” debate in Japan? How does the Aegis Ashore suspension fit into that ongoing conversation?

The cancellation of the Aegis Ashore program is just the beginning of what has reignited the debate on strike capabilities. Although there has been a persistent argument that Japan should have a long-range strike capability, the debate on strike capabilities has not deepened as the Japanese government has prioritized low political hurdles in the past to improve its missile defense-focused capabilities.

As a result, the debate on strike capabilities in Japan has lacked discussion of strategic and tactical objectives, expectation control on deterrence effects, specific target selection, and the practicality of operational and budgetary constraints. These had been shared by only a few experts.

How much of the strike capability line, pushed by former Prime Minister Abe Shinzo, is due to domestic politics rather than external threats?

Abe left many legacies behind, including the security legislation that allowed for the limited use of the right of collective self-defense He was going to make starting a debate on the strike capability a final legacy.

But he was originally obsessive about security policy, and it wasn't a sudden idea to improve his approval ratings. It was an appropriate decision, given the difficult security environment Japan is facing. Therefore, domestic political factors are not as significant.

What kind of missile threats does Japan face and besides Aegis Ashore, what options does Tokyo have to defend against such threats?

Although it cannot be discussed in detail, Japan’s interceptor capacity is extremely limited. Japan’s missile defense system was built with aim of specifically countering North Korea, and until now, the Japanese government continues to follow that explanation.

However, North Korea’s theater-range ballistic missiles, which can strike Japan, have been significantly upgraded in quality and quantity over the past 10 years. As of 2017, North Korea had up to 150 short and medium-range ballistic missile (MRBM) launchers. It is likely, however, that as of March 2020 North Korea has already been producing new solid fuel ballistic missiles, further upgrading its simultaneous launch capability.

North Korea’s increase in MRBMs will place a heavy burden on Japan’s missile defense capacity. The Aegis ballistic missile defense (BMD) has been proven to have a high intercept success rate of more than 80 percent for single or a few MRBM targets, making it a relatively reliable system. Missile defense, however, is saturated and defeated when the number of interceptors is overwhelmed, the simultaneous interception capacity is overwhelmed, or the radar resources are overwhelmed.

Furthermore, SM-3 is a very expensive interceptor, costing more than $20 million per BIock1B missile, and more than $40 million per Block 2A missile, which is the latest variant and has a wide interception range. Therefore, the introduction of SM-3, which is capable of preventing all of North Korea’s MRBMs, would impose an extremely large cost on Japan. It is clear that North Korea’s cost of producing a MRBM, including a mobile missile, is far more efficient than Japan acquiring a SM-3.

If Japan tries to build air and missile defense architecture that relies solely on defensive capabilities to counter China, Japan will face a greater shortage of interceptor capacities. According to the U.S. Department of Defense, China has more than 1,250 ground-launched ballistic missiles (GLBMs) and ground-launched cruise missiles (GLCMs) with ranges between 500 and 5,500 kilometers. In addition, it is expected that they also have more than 700 road-mobile missile launchers. Furthermore, the burgeoning number of Chinese bombers and destroyers are also capable of launching cruise missiles, and more recently, those capable of launching ballistic missiles have been developed.

Unlike ballistic missiles, which need to be aligned in the direction they are to be launched, cruise missiles can change direction mid-flight route, so early warning for all directions is necessary. This imposes significant costs on defenders. If the missiles are fired repeatedly, Japan (and forward-deployed U.S. forces) would soon have exhausted its interceptors’ magazine capacity.

Moreover, theater-range hypersonic weapons that China has recently begun to possess – whether they are hypersonic glide vehicles or hypersonic cruise missiles – shorten warning and reaction times on the defender side. These weapons impose significant costs on the defender side and dramatically tip the scales of the offense defense balance to favor the offense.

Given the recent security environment in Japan, maintaining an exclusively defense-oriented policy is equivalent to narrowing one's options and waiting for one's position to become increasingly disadvantaged. Moreover, it is not enough to establish counter-attack capabilities targeting only North Korea.

These points do not deny the effectiveness of missile defense. However, missile defense does not by itself constitute an effective air defense operation. Effective comprehensive air and missile defense operations work only when five key elements combine in a balanced manner. These are early warning, missile defense, civil defense, deterrence by punishment through retaliation, and counterforce, which imposes restrictions on the adversary’s strike capability, combined in a balanced manner. Of these five, deterrence by punishment is currently provided by U.S. extended deterrence, or the U.S. “nuclear umbrella,” which would ensure a retaliatory response to any state that launched a nuclear attack on Japan. In the event of nuclear attack on Japan, the survivability, range, and accuracy of U.S. assets will outmatch Chinese capabilities.

However, it is unlikely that China would suddenly launch a nuclear attack against Japan in the early stages of an armed conflict in the Western Pacific. The most likely scenario is for the PLA to carry out a conventional missile salvo in conjunction with other disruptive attacks in domains such as cyber, space, and electromagnetic. Furthermore, China’s A2/AD capabilities outpower the United States’ conventional regional strike capabilities, which consist of tactical aircraft based on air bases or aircraft carriers. Therefore, if Japan seeks to possess long-range strike capabilities, it is necessary to consider not only optimization of Japan’s defense resources but also how to bridge the strike gap between the U.S.-Japan alliance and China.

To specifically focus on defense capabilities, the MOD is struggling to find alternative options for Aegis Ashore.

Several options are possible. The first is to build two additional BMD-capable Aegis destroyers. This option doesn’t need to worry about local opposition. However, it’s the main reason why the Aegis Ashore was needed in the first place, because it didn't add more mission burdens on the understaffed MSDF. It also takes more time from the time the ships are started to be built until it is commissioned.

The second option is the tricky option of building a ship dedicated to the missile defense mission. This option envisions something like a “missile defense patrol ship” that would focus on missile defense missions in safe nearshore Japanese waters, rather than the high specs of a regular Aegis destroyer conducting high-end missions in the open sea.

Some have cited cost savings, personnel reductions, and the possibility to divert the SPY-7 radar that they've begun to acquire as advantages. However, in my opinion, these would not prove true. A large part of the cost of the Aegis destroyer is the Aegis Combat System, which has next generation digital radar at its core, and building such a vessel would not be a significant cost savings. Likewise, it would require a significant MSDF crew.

The most realistic option is to deploy the SPY-7 radar on the ground as planned and the missile launcher, MK41VLS, elsewhere. Originally, the latest Aegis systems were given a feature called “Engage On Remote.” This concept is designed to optimize the launch location of an interceptor missile by providing a near real-time data link between sensors that detects incoming missiles and a ship or launcher at a remote location.

Where the launcher should be deployed is related to what it will protect within the intercept coverage of the interceptor missile. For example, deploying the launcher away from the radar could protect Tokyo or large population areas from ballistic missile attacks, but it would be out of SM-6’s coverage to intercept cruise missiles aimed at the radar, requiring a new other air defense system to be deployed to protect the radar itself.

Despite those disadvantages, they could minimize the risk of dropping boosters by deploying just the launcher along a different oceanfront.

U.S.-Japan host nation support talks are looming. Will the Aegis Ashore suspension impact those discussions?

Negotiations on Host Nation Support will not move significantly until the finish of negotiations between the U.S. and South Korea, and then after the U.S. presidential election.

Recently at RAND, Defense Secretary Esper said, “We urge you to increase your defense spending to at least 2 percent of GDP, and to make the needed investments to improve your capabilities and capacity, just as we are doing with our armed forces, to achieve our shared goals – that is to protect our mutual interests, preserve our security, and defend our common values.”

Even if the 2 percent of GDP level defense spending cannot be achieved immediately, it is only natural for allies to increase their self-help efforts in light of the increasingly difficult security environment Japan is facing. Japanese and U.S. policy practitioners in the negotiations will try to separate the Aegis Ashore issue from the HNS issue so that it does not become politicized.

Japan already contributes nearly 75 percent of the cost of U.S. military facilities and personnel in Japan, and is unable to increase that amount.

If that is the case, then the idea of increasing the burden on a mission basis would be a possibility. Mission-based burden-sharing could involve (1) covering the costs of U.S. operations, (2) having the SDF replace U.S. operations, or (3) using Japan’s budget to pay for the maintenance of assets and facilities used by the U.S. and Japan for joint/combined operations.

The idea of shouldering the cost of U.S. operations covers the cost of deploying bombers, carrier strike groups, and satellite constellation and so on. This has been criticized as turning the U.S. forces into mercenaries, but it would not be a bad deal if Japan could partially participate in the operation and planning of U.S. strategic bombers and ballistic missile submarines on the condition that it bears the operational and deployment costs of the U.S. forces.

Japan should not only seek reassurance from the United States but should reassure its ally through its own efforts to continue to encourage the United States to continue its commitment to security in this region. In the face of serious missile threats from China and North Korea, strengthening Japan’s effort to missile defense and defeat would signal a willingness to allay the risk of U.S. political leaders and the U.S. public.

The U.S. and Japan will have to make massive expenditures to recover from the pandemic and the economy is stagnated. I do not believe that current defense spending level is sufficient against the security environment which Japan faces, but the reality is that it will be difficult to significantly increase defense spending during an economic downturn. In other words, Japan and the United States no longer have the luxury of building their own defense capabilities independently of each other, and they must be more efficient in building and operating their own defense capabilities, given the constraints on each other’s defense resources. This will require the U.S. and Japan to share a “theory of victory” regarding how to deal with China and North Korea, to recognize what shortfalls exist in achieving them, and to redefine how the U.S.-Japan alliance will share and divide each other's roles, missions, and capabilities. This needs to be done prior to all discussions.

This interview has been edited for length and clarity.