Independent consultant specializing in international security affairs. The author recently completed a study on urban violence in the developing world for the Office of Transnational Issues, United States Central Intelligence Agency.IN HIS ARTICLE, 'The international politics of missile defence: a response to the critics' in this journal (autumn 2000), Frank Harvey critiques the arguments made by opponents of current United States plans for a limited deployment of national missile defences (NMD). According to Harvey, such arguments are weak, frequently misleading, often logically inconsistent, and, at times, beside the point. Consequently, he contends that the case against missile defence is not sufficiently convincing to challenge seriously a continuation of the American programme.Harvey provides a much-needed stimulus to more informed debate on an increasingly salient and important issue, but many of his contentions do little to undermine decisively the various concerns that missile defence has generated. Nor for that matter, do his arguments against the critics translate into a strong case in favour of deployment. In fact, at the end of the day, his contentions raise as many problems as the arguments he challenges.IMPACT ON EXISTING REGIMESThe author's treatment of claims that NMD threatens the demise of existing arms control and disarmament regimes offers a case in point. According to Harvey, such concerns are overblown - obscuring the varied and often complex motivations and incentives that have historically driven nuclear proliferation. The fate of regimes such as NPT will not hinge on NMD deployment (p 548). Rather, they will depend on developments taking place within the particular political, military, and security contexts that other states occupy.Clearly, recognizing that forces leading to nuclear proliferation often vary according to national and regional context is wise. But to imply that a decision to deploy NMD cannot impact on such security environments seems equally overdrawn - suggesting in effect that developments in one region will have little or no impact on others. Harvey's stance is especially curious in light of the fact that opposition to United States plans is regularly expressed in many of the nations that critics claim would pose proliferation dangers in the event of deployment (for example, Russia, China, Pakistan, North Korea). Even if opposition never translates into concrete action, assertions that such actions will not occur seem premature at least.Elsewhere, the author's point seems less that arms control treaties will go unharmed by NMD than that the shortcomings attending such agreements will ensure that any negative impacts will not matter. Thus, Harvey notes that both the Nuclear Non-Proliferation and the Anti-Ballistic Missile treaties have been accompanied by an increase in both vertical and horizontal proliferation (p 547). And recent instances of proliferation in south Asia indicate that the worst may be yet to come.This seems excessively harsh and obscures the extent to which such regimes have provided a degree of predictability and stability in security relations that might not have existed in their absence. It also ignores the possibility that there might be more nuclear weapon states if such regimes had never been created. Most significantly, Harvey's comments do little to bolster his central contention that NMD will not have a negative impact on these treaties. Indeed, they imply precisely the opposite. Nor, for that matter, do they say anything about the capacity of such deployments to provide a level of national security that is equal to or that exceeds the security offered by the regimes he criticizes.In fact, if Harvey applied the same yardstick to missile defence that he uses to judge the utility of arms treaties, evidence of their effectiveness could prove just as elusive. Beyond the obvious benchmark for evaluating NMD effectiveness, that is, the successful destruction of incoming nuclear missiles during an enemy attack, one might be hard pressed to establish decisively that deployment of such a system would offer any appreciable gain in deterrence. …