Nuclear Strategy as a Constraint on Japanese Nuclear Armament.

The assumption that the balance of material costs and benefits of nuclear armament for Japan is sensitive to small changes in the scope and credibility of U.S. extended deterrence supports the current role of nuclear weapons in U.S. national security and military strategy. This paper scrutinizes this assumption in terms of a constraint that is especially difficult to change: what kind of deterrent strategy can Japan implement against nuclear weapon states? I start with pessimistic assumptions about the need for an independent nuclear deterrent, and optimistic assumptions about the feasibility of building nuclear weapons, both of which are crucial for prediction and advocacy of nuclear armament. The first set of assumptions, in which the United States no longer extends deterrence, and China values victory in nuclear war against Japan, rules out a small force de frappe for Japan. Instead, Japan will need a large retaliatory force, even with an asymmetric counter-recovery strategy against energy resources, transportation, and sea power. This deterrent is not likely to become operational without a decade of investment. In short, a claim that a small nuclear deterrent is necessary and sufficient for Japan contradicts itself. Japan needs either a large nuclear deterrent, or none of its own. [ABSTRACT FROM AUTHOR]