Helen Frowe's critique of jus ad vim suggests that such a framework is redundant when just war principles are understood “correctly.” My own view remains that jus ad vim is essential to understanding the ethics of force today.Footnote 1 I think our difference in opinion about the rules that should guide the use of force is rooted in two fundamentally divergent worldviews. While I will respond to many of Frowe's points below, let me begin with praise for her engagement, which has pushed me to think more deeply about the original argument, in particular whether it could be justified to escalate from vim to bellum and about pinpointing what jus ad vim contributes to our moral reasoning about the use of force.
Frowe argues from the revisionist just war position, accepting that this is the correct interpretation of just war principles. Revisionists reject the view that the state of war grants special privileges to those doing the fighting. Revisionism turns instead to a moral concept of liability and reformulates the ethics of violence in war in terms of individual responsibilities and rights.Footnote 2 It is worth noting that Frowe's critique is not simply aimed at jus ad vim; it is much bigger than that. Rather, she implies that any just war logic other than the revisionist viewpoint is flawed (page 122). The assumptions underpinning this claim are highly contested in the literature, to say the least. As others have argued, this view misses something important about the realities of war and is simply too impractical to be applicable to the entire continuum of violence in the international realm.Footnote 3
Unlike Frowe, I do not see the revisionist view of just war as an ethical model that applies across the spectrum. My own view is grounded in an empirical observation about how violence is adjudicated in international society. I take as my starting point Walzer's analysis of just war, which Frowe rejects. Ethical debate about state use of force has long distinguished between the conditions of peace and war, with different ethical frameworks governing each.Footnote 4 In the former, the ethical constraints of law enforcement shape the extent to which a state can use force against a suspected criminal, while in the latter the laws of war apply to combatants on both sides.
My original attempt to theorize about jus ad vim emerged from another empirical observation: that there exists a gray area between law enforcement and war in which the moral rules are unclear. The U.S.-led drone campaigns are an illuminating example. The government speaks the language of just war to defend targeted killing, but as I argue elsewhere, there is something deeply troubling about its doing so.Footnote 5 To clarify this area, I sought to theorize about whether and, if so, how, the morality of limited force differs from that of war.
The Critique
Frowe offers several critiques of jus ad vim, the two most significant being that it does not tell us anything new about proportionality and that the criterion of escalation is already part of just war thinking. She then proposes to look at drones—though a significant discussion of actual drone use is conspicuously missing from her analysis—to further support her claims.
Reconsidering Escalation (and Proportionality)
Frowe argues that there may be cases in which it is justified to increase the use of force to counter a changing and growing threat. This point is well taken. The fallout from recent events is significant in this regard: the debates in Great Britain about whether to bomb ISIS in Syria, as well as the United States' willingness to weaken the rules of engagement to bomb soft targets and deploy special forces to fight the same group, attest to the contemporary importance of understanding the criterion of escalation. President Obama's need to clarify that sending fewer than fifty special operations troops to Syria is not the same as ordering a ground invasion points, I think, to a general opaqueness in the public sphere about the use of force. Thus, the larger underlying philosophical concern at issue here, and which jus ad vim seeks to address, is defining what exactly war is (and, consequently, which rules apply).Footnote 6
In our initial article on jus ad vim, Megan Braun and I raised more questions than we answered regarding escalation.Footnote 7 Indeed, I think the just war tradition (and the contribution of jus ad vim to this body of thought) is more about discerning the important questions about organized violence and providing a moral vocabulary to think through them than delivering philosophically definitive answers. Thus, the reason for focusing on escalation as a separate criterion of jus ad vim was twofold: to scrutinize the moral reasoning involved in moving from, say, a policy of targeted killings and arming rebels to one of widespread bombing and (perhaps) to a full-scale ground invasion; and to provide a moral vocabulary to analyze this process. When we postulated that “if engaging in jus ad vim actions has a high probability of resulting in war, then one could argue that such actions are not justifiable, and must be subject to the stricter jus ad bellum regime,” we aimed to set an ideal position, a point of departure for thinking about employing limited force. We later implied that following this schema may not be theoretically tenable in all cases, a point that Frowe duly recognizes. The main idea, however, was to oblige those wielding limited force to think about the possibilities of escalation before using it—not once force has already been employed.
Frowe's concern is nicely formulated in the form of two questions. She asks, “Should our concern really be whether measures short of war escalate into war? Or whether they escalate into more serious—and disproportionate—uses of force?” (page 122). She asserts that all we need do is calculate what a proportional response would be. But this is precisely the problem. Calculating proportionality (whether ad bellum or in bello) is not as easy as she intimates (even with weapons as accurate as drones). Frowe is apt to point out repeatedly that one form of proportionality arguably cuts across all realms of violence, whether within a civil context or on the battlefield. This is not, however, the way the “system” operates.
In liberal societies police forces are trained differently than military personnel, and each has different rules of engagement. The international system is structured according to rules that differentiate between times of peace and times of war (admittedly not ideal, but rules that nonetheless provide a moral and legal language that politicians turn to in order to justify violence). Frowe objects that jus ad vim (and other ways of thinking about just war) places unwarranted weight on whether something counts as war, but there is a good reason for doing so—namely, that the system is structured to allow certain privileges in war that are not allowable otherwise. The analytical starting point of jus ad vim is identifying certain categories of violence as falling short of war, and thus not governed by these special privileges. I believe that the task that follows is to explore what (more restrictive) standards should govern these categories. Frowe, on the other hand, begins by considering the use of force between individuals, asserting that we should judge the ethics of killing in war by the same moral rules that govern this relationship. However, the main example she uses to explain her point—Grenade and Provoke—skirts the issue at the heart of jus ad vim, that is, how states evaluate the use of limited force in response to a significant injury received or a meaningful threat. First, her example abstracts the moral concern to the point of having seemingly nothing to do with the use of limited force in the international realm. All one has to do is replace the injuria from something trivial (pinching an arm) to something truly significant (shooting up cafés and music halls in Paris or anywhere else in the world) to muddy the philosophical waters. Moreover, it reduces the acts of violence to individual agency, a move that occludes one very important factor: violence on the international stage occurs by and large at the level of collectivities. To be sure, individuals do the killing and the dying, but collectives (states, nonstate actors, multilateral security organizations like NATO) bear the moral responsibility for the broader decisions and consequences. The kind of violence that just war scholars seek to understand is, above all, a social activity.Footnote 8 Reducing this to individual agency does a disservice to the much more complex questions that practitioners and soldiers must answer to, and sidesteps the social consequences that force, limited or otherwise, imposes on those who bear its brunt.
The CIA drone program is a case in point. While proponents routinely claim it satisfies jus in bello proportionality, Megan Braun and I have argued that it should not be judged according to these standards, but rather according to jus ad vim. If it were judged by jus ad vim, “the CIA's proportionality calculus would fail to uphold the strict relationship between the use of force short of war and the jus in bello principles that jus ad vim requires.”Footnote 9 Frowe has two concerns with this line of reasoning. First, she claims that we misunderstand just war principles by not adopting the (contested) revisionist position. However, as I have argued elsewhere, the drone debate is largely framed by questions about whether traditionalist just war principles or those of law enforcement apply.Footnote 10 Again, the problem of what war is (and what rules apply) frames the issue.Footnote 11
Second, Frowe suggests jus ad vim is redundant because the use of force that fails ad vim proportionality will also fail ad bellum proportionality. But this is not a theoretically interesting scenario. What is interesting is the converse case: an action that satisfies jus in bello proportionality, but not jus ad vim. This, Megan and I argue, is the status of the CIA drone program (at least up to 2012).Footnote 12 Of course, one could simply say, as Frowe does, that practitioners misunderstand the concept of proportionality and that we should not base our moral analyses on their mistakes, but again, this sidesteps the issue at heart, namely, that the international system is structured according to the view that war is a privileged arena, and practitioners can abuse this privilege. We may wish this to be otherwise, and we should seek ways to offer moral clarity—a point both jus ad vim and revisionist just war thinking have in common; and a point, in my view, to build constructively from.
The Contribution of Jus ad Vim
I have already highlighted the different presuppositions behind the jus ad vim project and revisionist just war thinking. Here I want to offer a way to bridge them. If we think of limited force as conceptually distinct from other types of violence, then, paralleling the categorical divides in just war thinking, we need to theorize about jus ad vim, jus in vi, and jus post vim. The primary goal of the jus ad vim project thus lies in exploring how drone strikes, special forces raids, and air campaigns of limited duration can be employed in more ethical ways. I think doing so can show some overlap between the ethical considerations I propose and the aspirations of the revisionist project.
If the conduct of limited force were governed by jus in vi, the right to kill would be circumscribed by limiting the category of legitimate targets. Rather than allowing the killing of all combatants, jus in vi could prescribe a finer differentiation, demanding that the attacking belligerent identifies and targets only those combatants who have actively contributed to the threat. Alternatively, while in war any soldier is fair game, in a context of limited force only those who are a threat—that is, liable for unjust harm—could be targeted. In addition, jus in vi could diverge from jus in bello by proscribing the unintended killing of civilians entirely. While this is widely considered unrealistic in war, some of the forcible alternatives to war such as special forces raids, drone strikes, or circumscribed air campaigns could conceivably operate with a requirement of an expectation of zero incidental civilian harm. To conclude, the jus ad vim project could help bridge the theoretical divide between competing just war camps by identifying contexts where there is significant agreement on what is morally permissible. To the extent that uses of force that fit the traditional understanding of war may occur less and less frequently, this shared moral space may grow. By focusing on what the two paradigms have in common, proponents of jus ad vim can benefit from the philosophical rigor characteristic of the revisionists, while the revisionist project can overcome one of its main weaknesses by scaling down the claim that its premises can accurately apply to all different types and levels of violence, and focus instead on contexts where these premises are in fact actionable: namely, that gray area between law enforcement and war.
