Advanced Conventional Weapons, Deterrence and the U.S.-Japan Alliance

advancedconventionalweaponsdeterrenceusjapanalliancerowberry_coverIn this report, Ariana Rowberry, a 2013-2014 Herbert Scoville Jr. Peace Fellow, analyzes the potential contribution of Japanese conventional strike systems and ballistic missile defense capabilities to strengthening the U.S.-Japan alliance.

The report begins with an overview of the alliance, examining the various components of the extended deterrent, including nuclear, conventional and political deterrence. Next, it examines the evolving security environment in Northeast Asia and suggests that advanced conventional weapons could have an increased role in responding to the altered environment. The report then analyzes the costs and benefits of the potential contribution of Japanese conventional weapons systems to the U.S.-Japan alliance.

Rowberry concludes that the United States and Japan should engage in deeper consultation via existing consultative forums, and actively explore the potential role of advanced conventional weapons systems in the U.S.-Japan alliance. Presently, because of high political costs and technological challenges, she suggests that Japan should not consider developing an indigenous conventional strike capability. However, in the long-term, it could be advantageous for Japan to acquire a conventional strike capability, particularly if the security environment in Northeast Asia becomes increasingly unstable.

Rowberry recommends that the United States and Japan continue to strengthen coordination on ballistic missile defense. Should the Japanese government reinterpret the constitution to adopt collective self-defense, Tokyo could use its existing ballistic missile defense systems to protect U.S. bases in Northeast Asia. Finally, when political circumstances permit, the United States, Japan and South Korea should work to assuage old wounds and establish a formal mechanism to discuss military cooperation, and seek to cooperate on ballistic missile defense in the long-term.