The Debate

Japan: Dealing with North Korea’s Growing Missile Threat

Time for Japan’s political leaders to do their job.

By Koda Yoji for
Japan: Dealing with North Korea’s Growing Missile Threat
Credit: AP Photo/Eugene Hoshiko, File

On June 15, then Defense Minister Kono Taro suddenly announced his decision to back away from building two sets of land-based ballistic missile defense/intercepting (BMD) sites that would cover virtually the entire territory of Japan. Many arguments about how to defend Japan from North Korea’s expanding missile threats have been made since then. One of the options put forward by certain members of the ruling Liberal Democratic Party (LDP) is to give the Japan Self-Defense Forces (JSDF) strike capability to defeat/destroy ballistic missiles and other weapons in the territory of the aggressor nation.

Legal Aspects

There is indisputably a consensus in Japan that the JSDF is prohibited from conducting strategic strike operations on enemy soil under the current war-renouncing Constitution. In this context, it has been the exclusive role of U.S. forces under the Japan-U.S. alliance to act on behalf of the JSDF and conduct strategic strike operations against an enemy nation to weaken its attack capability. This strategic complementary mission-sharing posture has been widely referred to as a “Spear and Shield” relationship.

The Japanese government has acted in strict compliance with the national consensus. However, as a hypothetical argument in Japan, the government’s interpretation of the Constitution in the context of an attack on enemy soil in an extreme situation is not as simple as merely adhering to the common consensus. In one key remark, Prime Minister Hatoyama Ichiro’s administration stated to the Diet in 1956, seven years after the JSDF’s foundation:

Even under the war-renouncing Constitution, it is possible for Japan to attack enemy installations under certain limits to forestall a deadly attack like a ballistic missile attack if there is a clear and present danger that Japan would face such an attack and when there are no other means to protect the country from this danger.

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As an extension of this tenet, there have occasionally been controversies in Japan’s political community over the JSDF’s strategic strike capability on enemy soil in an extreme situation. Having said this, however, it is also true that every Japanese government in the past has made its position clear: both preemptive and preventive strikes on enemy soil are strictly prohibited as practical government policy, while keeping Hatoyama’s tenet as a hypothetical argument or as a last resort. The Cabinet of recently departed Japanese Prime Minister Abe Shinzo was no exception.

Chronology of Japan’s BMD

After Pyongyang’s bug fix and updating of its nuclear development attempts in the early 1990s, Japan started taking North Korea’s nuclear weapons and ballistic missile development into serious security consideration. In August 1998, North Korea launched a Taepodong ICBM that flew over northern Honshu (Japan’s largest island) and landed in the Northwestern Pacific. A JMSDF Aegis destroyer successfully tracked the missile. This event changed Tokyo’s threat perception of NK’s missiles from hypothetical to real.

Thereafter, the Japanese government launched a number of initiatives that included Japan-U.S. joint research and development of BMD systems. The government also upgraded both Aegis destroyers and Patriot anti-air missile systems to BMD configurations. The latter is referred to today as Patriot Advanced Capability-3 (PAC-3). These two anti-ballistic missile systems remain the only BMD systems in Japan. The two systems constitute the layered BMD posture of Japan; that is, the shipboard Aegis as long-range/high-altitude interceptors and the ground-based PAC-3 as short-range/low-altitude weapons against North Korean ballistic missiles.

The systems were fielded in and around Japan to track and monitor every North Korean ballistic missile launch in 2017, and the two BMD systems proved their capability. However, these were no more than ad hoc measures to tentatively counter wild launches. There were no dedicated full-time BMD systems in Japan.

To overcome this handicap, the Japanese government decided to introduce two sets of shore-based Aegis systems as dedicated BMD systems that would maintain 24-7-365 BMD alert, in December 2017.

Based on this decision, Japan’s Ministry of Defense started preparatory work to introduce and build the shore-based BMD systems.

One of the key points to remember in this process is the fact that the shore-based BMD system which the JMOD selected was substantially different in system configuration from the U.S. Navy-developed BMD system that is widely referred to as Aegis Ashore. In particular, the Radar and Combat-Control sub-systems were substantially different from the USN’s systems. In this context, it may not be correct to designate Japan’s shore-based BMD system as an Aegis-Ashore. In theory, the BMD system should be referred to as Japan’s Shore-Based BMD system.

Whatever the case, after two and a half years of long, laborious preparation in the JMOD, Kono decided to stop the program and made the sudden announcement that the JMOD was backing away. The decision triggered much debate in Japan, including the aforementioned proposed introduction of a strategic strike capability to the JSDF as an alternative to the aborted Shore-Based BMD system.

Critical points

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It has not been the primary objective of observers to ask why Kono made his “no-go” decision, except to inquire about his thinking on the impossibility of preventing a missile-booster from falling on local housing. However, there have been many questions and doubts expressed in Japan about the JMOD’s decision on Japan’s Shore-Based BMD system since its selection in the summer of 2017. It is clear that the JMOD’s lack of transparency in its system selection contributed to making the current confused situation much worse than it would otherwise have been. This author believes that this poor and irresponsible maneuver by the JMOD explains the lion’s share of the current troubles with regard to BMD. The JMOD should be frank about the reasons why it picked up a non-existing paper system still under development over the USN’s existing Aegis Ashore system.

When it comes to the LDP’s appetite for strategic strike capability, it is understandable that even under its war-renouncing Constitution, Japan as a sovereign independent nation has a fundamental right to attack enemy soil under the aforementioned extreme situations. However, it is also clear that jumping on this capability as a single alternative to an aborted Shore-Based BMD system would be a short-circuit response and impossible to realize politically.

There are many steps necessary for Japan’s political leadership to justify and convince the Japanese people to introduce this capability, if it is proven to be the most suitable defense system for Japan from all aspects.

In other words, BMD and strike capability on enemy soil are just tiny elements of Japan’s overall defense posture. There are many other elements for the government to consider. The political leadership should examine all elements of national defense from every aspect.

These elements include the national defense concept, security/defense strategy, and threat assessment as conceptual subjects. It is also essential to consider the strategic mission-sharing concept under the Japan-U.S. alliance. As operational features, both joint operational doctrine and the capability of the JSDF within the joint forces should be  examined carefully. With regard to the JSDF’s force build-up, the size/limit of the defense budget, budgeting priorities among major defense systems/equipment, as well as logistics and education/training of service personnel are major elements to consider.

These are just a few of the overwhelming number of “must be considered” elements. Unfortunately, they rarely seem to come up within the LDP. The JMOD should conduct a detailed examination of these subjects and provide the best options; for example, a Plan A, Plan B and even a Plan C, to national decision-makers and the Japanese public.

The LDP’s recommendation on the JSDF’s capability of attack on enemy soil this time clearly lacks the necessary scrutiny, and as such is less than convincing. In short, it remains a “pie in the sky.”

There is only one way for the Japanese government to convince the Japanese people of the need, or otherwise, to introduce this capability. The government and political leaders must stay fully on top of the process and exercise healthy civilian control over the JSDF, as is the right of the Japanese people.

Koda Yoji is the former Commander in Chief of the JMSDF Fleet.