By VADM (ret.) Yoji Koda, JMSDF


It is my estimate that, even around 2030, the alliance between Japan and the United States will remain a core enabler of the security of the Asia-Western Pacific region. The division of labor between Japan and the United States with respect to fundamental roles and missions – i.e., the defensive power of Japan and the offensive power of the United States, US nuclear deterrence, and Japan’s responsibility of providing military bases to the United States – will be maintained over the next two decades. However, if the future world includes new challenges of precision strike and nuclear weapons proliferation, there will be several issues for Japan to consider that have not been recognized as problems in the current alliance posture.

Precision strike

In Japan, the requirement for defense against precision strike was for a long time overshadowed by the Cold War nuclear competition between the United States and the Soviet Union. In addition, the capacity for longer-range precision strike was considered a monopoly of the United States during the Cold War, and the Soviet Union, which had some relevant capabilities, was well deterred by the strategic balance.

Contrast that with the situation today. China will gain longer-range precision strike capabilities before 2030. If other regional nations also join the precision strike club by that time, this will greatly complicate Japan’s defense planning. It is especially the precision strike capability provided by long-range cruise missiles (CM) that will pose a security problem for Japan. North Korea, Russia, South Korea, and China all may develop or further develop precision weapons utilizing cruise missile delivery systems in the next two decades. For Japan, relative to Ballistic Missile Defense (BMD), which has been an example of successful Japan-US cooperation, building an effective defense network against precision strike will be more difficult.

In this situation, some may wonder if more than before aggressive voices within Japan will argue that Japan should obtain its own strategic CM striking capability. It is certain that an increasing number of Japanese will support this opinion; however, if the Japanese and US governments make a strong case for the continued credibility of the alliance, this hard-line trend of opinion will not become a significant political factor.

Nuclear weapons proliferation

It is just a matter of time before Japan will be targeted by North Korean nuclear-armed ballistic missiles. Japan was targeted by Soviet nuclear weapons in the Cold War and, possibly, faces a similar threat from Russia and China today. So nuclear weapons proliferation is far from a new issue for Japan; however, if such proliferation expands to other regional nations, this will be serious problem.

A key question for Japan will be whether to remain a non-nuclear nation in the face of the spread of nuclear weapons in the Asia-Pacific region. In such an environment, the following points would have to be considered.

First, what are the costs and benefits of becoming nuclear-armed? It is clear that Japan would lose much more than it would gain in such a situation. Remaining a non-nuclear nation under the current alliance with the United States would be a much wiser and more practical decision for Japan.

Second, a key issue for Japan and the United States in this environment will be how to continue to convince the Japanese people of the credibility of the US nuclear deterrent. Some in Japan have expressed growing concern about the status of the US deterrent, and, unfortunately, neither government has made sufficient effort to convince people about the deterrent’s reliability. In particular, since Prime Minister Koizumi’s tenure, the government of Japan (GOJ) has not adopted any productive reassurance measures, and if this situation continues, a majority of the Japanese people might have a strong appetite for an independent nuclear weapons capability. Both Japan and the United States should take this risk into account, and should resume bilateral nuclear dialogues as soon as possible.

Concluding thoughts

Japan will have several options for meeting the challenges of the emerging security environment. New measures should be taken to keep highly trained and operationally capable US forces in the region to counter emerging anti-access/area denial (AA/AD) strategies. These would include an at-sea BMD to protect the US Navy’s Carrier Strike Groups. Also, a more robust anti-submarine warfare (ASW) capability against the latest submarines should be developed. In addition, protective measures to secure and maintain the command, control, communications, computers, intelligence, surveillance, and reconnaissance (C4ISR) capabilities of allied forces against an electro-magnetic pulse (EMP) attack in the region should be established. EMP is not widely discussed yet but will be a good tool to neutralize allied C4ISR nerve centers and networks. Finally, construction of a defense network against precision strike will also be critical for future Japan-US cooperation. Efforts along all of the above lines will enable the future operational and strike capabilities of US forces deployed in the region.

One last idea is to develop Japan’s own AA/AD capabilities. For example, Japan could develop long-range anti-ship cruise missiles to counter an adversary’s naval and carrier strike forces, and also deny their freedom of movement. Conventional submarines and vast numbers of modern sea-bed mines would be Japan’s other AA/AD assets. These are just some parts of a potential suite of Japanese AA/AD tools in the 2030s. In this context, without taking “eye for eye” measures, there are several flexible options to meet future security challenges, while maintaining Japan’s long-established defense-only posture under the alliance. This could be the Japanese version of Asymmetric Warfare.

Yoji Koda is Vice Admiral (ret.), Japanese Maritime Self-Defense Force.