The Utility of Nuclear and Conventional Forces in the Second Nuclear Age: A Japanese Military Perspective

Abstract

In recent debate on Japan's security policy, proliferation of WMD and their delivery means, such as missiles, has been one of central issues. This issue is particularly critical to Japan, given North Korea's acceleration of its nuclear weapons program alongside its long-range missile project. Japan's new National Security Strategy (NSS) and National Defense Program Guidelines (NDPG) focus on both nuclear proliferation and emerging nuclear threat posed by North Korea. At same time, tension between Japan and China in East China Sea has been increasing, while tensions between China and countries in South China Sea have similarly been on rise.This essay will present a Japanese perspective on nuclear dimension of regional security by, first, explaining Japan's nuclear-related policies; second, discussing roles of nuclear forces in Japan's security policy; and, third, exploring Japan's security strategy for managing a possible stability-instability paradox in region, with particular emphasis on East China Sea.Japan's Non-Nuclear Policy and Nuclear ForcesOne of most important aspects of Japan's security policy since World War II is its non-nuclear policy based on non-nuclear principles, referring to principles of not possessing nuclear weapons, not producing them, and not permitting their entry into Japan.1 Not only does Japan adhere to these three principles as fundamental elements of its national policy, but Japan's Atomic Energy Basic Law also prohibits country from manufacturing or possessing nuclear weapons. Furthermore, Japan ratified Treaty on Non-Proliferation of Nuclear Weapons (NPT) in June 1976 and put itself under strict obligation not to produce or acquire nuclear weapons as a non-nuclear weapons state.Japan's possession of nuclear weapons, however, is not necessarily restrained by its constitution. While designed to make nation as peaceful as possible, constitution does not exclude outright Japan's pursuit of nuclear options. The government's basic interpretation is that Article 9.2 of constitution does not prohibit possession of force that is within minimum range necessary for self-defense.2 Therefore, if weapon in question, whether conventional or nuclear, is within these bounds, it is not constitutionally banned. If thus confined to minimum necessary level for self-defense, possession of nuclear weapons is considered constitutional for Japan. Here it should be noted that minimum necessary level applies to limit of individual self-defense and does not include collective self-defense in government's interpretation of constitution.The Role of Nuclear Forces in Japan's Security StrategyJapan has continuously relied on United States to deter nuclear threats against itself and has maintained that the extended deterrence of United States with nuclear deterrence at its core is indispensable.3 At same time, conventional elements of deterrence have become more important in recent years with dramatic improvements in technologies such as ballistic missile defense and precision-guided weapons. U.S. reliance on conventional elements of deterrence has increased alongside reduction in size of U.S. nuclear arsenal. Furthermore, as Japan improves its ballistic missile defense and other capabilities for deterrence by denial, it no longer needs to depend solely on nuclear forces to maintain credible nuclear deterrence. Although Japan currently has no intention of acquiring nuclear weapons, it is worth exploring why Japan would not be better off possessing its own nuclear option. This section of essay aims to clarify utility of nuclear weapons for Japan from a military point of view based on Robert Art's analysis of different roles of force: deterrent, defensive, compellent, and swaggering use.Deterrent use of nuclear weapons. …