From the perspective of black-letter international law, warfare is illegal unless it is a defensive response to ongoing or imminent military aggression perpetrated by a foreign power. While the line between standard defensive war and ongoing aggression is chiefly marked by international boundaries, the line that separates preemptive self-defense from an imminent threat of aggression is captured by the customary international legal standard of the Caroline test. According to this standard, states have a right to use force to repel an anticipated attack that creates a “necessity of self-defense” that is “instant, overwhelming, leaving no choice of means, and no moment of deliberation.” Preventive wars that are waged in anticipation of more remote future threats, no matter how probable, are by definition illegal acts of aggression, the ongoing mobilization for or imminent threat of which triggers the defensive rights of other states.
Yet, from any ethical perspective that includes a consequentialist dimension, there is a more general sense in which justifiable deployments of armed forces are nearly always “preventive.” Even when responding defensively to ongoing military aggressions, states seek to prevent harms that would otherwise likely befall them. Soldiers exchange fire with enemy forces in order to prevent harms to themselves, their comrades in arms, and whomever else they are fighting to protect. Why should the initial decision to deploy armed forces be any less preventive?
It is the conceptual and practical tensions between these two perspectives on contemporary warfare that enliven this excellent collection of essays from leading ethical, political, and legal theorists. Must states comply with the strict standards of international law when they have sound consequentialist reasons for waging preventive wars to avoid future threats of harm that are not yet imminent? Like other recent scholarship in this area, this collection also takes much of its impetus from the post-9/11 U.S. National Security Strategy, known as the Bush Doctrine, which famously blurred the line between preemption and prevention. This strategy declared that “America will act against . . . emerging threats before they are fully formed . . . even if uncertainty remains as to the time and place of the enemy's attack.”
After a helpful editorial introduction and overview by Deen Chatterjee, the volume's first of eleven essays features Jean Bethke Elshtain's cursory defense of the Bush Doctrine as a policy that purports to justify both the 2003 invasion of Iraq and the future prospect of war with Iran. She defends military action to prevent Iran from developing nuclear weapons because she imagines that this situation, along with the potential rise of radicals in the region, might “shift the balance of power ever more against Israel” (p. 25). She also argues that the invasion of Iraq was not illegal because “no state abrogates its sovereignty” when it joins the United Nations, and therefore every state remains judge of its own cause. On this view, it is difficult to see how any war could be illegal under international law.
Michael Blake's contribution complements Elshtain's view by systematically defending a skeptical answer to the question of what moral difference the putative illegality of preventive warfare under international law makes to the ethical decisions of states. He defends a contingent version of international philosophical anarchism, according to which the facts of international law do not create binding ethical obligations for states. For Blake, although states are not ethically obligated to comply with international law, they are obligated on grounds of epistemic responsibility to attempt to justify their wars to other members of the community of nations because failure to do so is “good evidence that the action proposed is illegitimate” (p. 86).
Less convincing, however, is his argument that, because the language of the Caroline case lacks the empirical content necessary to draw a meaningful temporal line, any preventive war with a consequentialist rationale that the international community accepts counts as legal preemption to all intents, constructions, and purposes. Contrary to what Blake claims about the Caroline standard, having no time to deliberate and having no nonmilitary options are in fact normatively significant “empirical attributes” of some circumstances, but not others.
Chris Brown similarly despairs of the task of formulating workable rules to govern the behavior of states in an “anarchic world,” and suggests as an alternative a wedding of political realism and Aristotelian phronesis or “practical judgment.” We must make difficult, all-things-considered judgments about the wisdom of preventive wars, while recognizing that history is replete with both good and bad examples. Whereas the 2003 invasion and occupation of Iraq was symptomatic of a “chronic failure of political judgment,” the 1998 Operation Desert Fox, aimed at Iraqi weapons capabilities, turns out to have been a great success because it convinced the Hussein regime to forsake its weapons of mass destruction programs (pp. 42–43).
In a politically pointed critique of the West's “threat diplomacy” against Iran, Richard Falk reminds us that, in forbidding military aggression, international law proscribes not only the actual use of anticipatory force but also the threat of it. Alex Newton's contribution complements Falk's by building a detailed legal case against the idea of launching preventive military strikes to disable Iran's nuclear ambitions. As in the case of Iraq, neither international law nor available intelligence lends sufficient support to this oft-proposed policy.
Larry May's excellent and wide-ranging essay draws on readings of Alberico Gentili and Hugo Grotius to prescribe two different standards for the International Criminal Court to consider when deciding whether to sanction states or prosecute their leaders for crimes of aggression when they have waged preventive wars. Whereas Gentili saw issues of just cause as largely subjective, and was therefore permissive about preventive wars, Grotius held that we can generally resolve issues of just cause as matters of objective normative fact. Consequently, Grotius was fairly strict about condemning preventive wars. Since prosecutions of individual political leaders tend to destabilize postwar transitions to lasting peace, May believes Gentili's more forgiving standard should apply. When deciding whether to sanction states for acts of aggression, however, Grotius's stricter standard is more appropriate.
George R. Lucas sifts through the “methodological anarchy” of the just war tradition for lines of ethical reasoning that support giving primacy to the human rights of individuals over the priority that international law gives to sovereignty and nonintervention.
Another outstanding contribution, which defies easy summary, is Jeff McMahan's penetrating analysis of the “liability” to preventive attack that may sometimes apply to soldiers who have joined the military but have not yet deployed. Although not entirely new, the piece further advances his deservedly influential work on the ethics of killing in war. C. A. J. Coady rightly objects, I think, to McMahan's method of constructing highly artificial counterexamples, which are “reminiscent of the ‘ticking bomb’ extravagances in the torture debate,” because this fanciful method opens up possibilities for real world rights violations (p. 200). Coady also takes to task those who would defend preventive wars by invoking poor analogies to disease prevention or criminal prosecution of domestic conspiracies; and he underscores the greater efficacy of nonmilitary means of counterterrorism.
Similarly, Deen Chatterjee rounds out the volume by embracing a strict noninterventionist perspective, criticizing just war theoretic arguments that permit even limited preventive wars, and calling for greater investment in nonmilitary methods of fostering “just peace.”
Finally, perhaps the chief theoretical highlight of the volume is Stephen Nathanson's rule-utilitarian defense of a strict international prohibition against preventive wars. He emphasizes the importance of employing the plurality of criteria to be found in “traditional” just war thinking (pp. 148–51), takes Michael Walzer to task for eviscerating the principle of last resort and reducing jus ad bellum thinking to the issue of just cause (pp. 151–54), notes that “immunity rights” should be given as much weight as “rights of self-defense” (p. 157), and makes a powerful case for concluding that a strict ban on preventive wars is what “would be chosen by rational, impartial people whose aim was to promote overall human well-being” (p. 165).
Given how much of this collection is devoted either to explicit (in Nathanson's case) or implicit (in McMahan's case) critical engagement with Walzer, it would have been nice to include a chapter from him; but that is a small complaint about a volume that already includes so much that will be of interest to so many readers.
