In this valuable new book, Neil C. Renic addresses one of the most important questions in the contemporary debate over drones: Is there anything about unmanned technology that changes war in a fundamental way? Answering this question is important because the debate over drones has reached a stalemate. On one side, there is a camp of scholars and activists who argue that drones are fundamentally novel and their diffusion presages an era of remote killing, the dehumanization of targets, and social and cultural dislocation from traditional concepts of war. On the other side lies a camp that argues that drones constitute an important technological advance but not one that will fundamentally change war. For these scholars, technology from the development of artillery to aerial bombing to nuclear weapons has long been heralded as a way to wage war without risking their own soldiers on the battlefield. Drones are little more than the next step in this trend and represent no greater challenge to the nature of war than what has come before.
Renic locates himself in the former camp and offers a theoretically rich account of why drones represent something new, even if they are not the only form of war-fighting technology to allow remote killing or dehumanization of the targets of violence. His argument is that drones represent “radical asymmetric violence,” a condition under which one side can inflict lethal force while enjoying the total absence of physical risk on the battlefield (pp. 31–38). This is different, he argues, from other forms of remote killing like sniping or aerial bombing, which drastically reduce but do not wholly eliminate physical risk.
Renic argues that, as a concept, warfare requires the prospect of mutual harm between collective combatants—for example, governments or ethnic groups—to be coherent. The use of drones for targeted killing by the United States abolishes the prospect of mutual harm because the United States faces no physical risk while using drones, in contrast to its targets, which remain profoundly vulnerable. A crucial part of Renic’s argument is that the absence of interpersonal risk does not upset traditional notions of warfare; there are plenty of cases, after all, of people participating in a war but located so far from the frontlines that they face no physical risk. Instead, it is the presence of what he calls “inter-belligerent risk”—that one side can collectively harm the other—that constitutes a structural element of warfare and must remain present for the normal ethical rules to apply.
One of Renic’s most provocative arguments is that radical asymmetry with drones poses a fundamental challenge to the applicability of just war theory. He argues that the just war tradition in all of its forms relies on a symmetry between enemies. This mutual recognition as combatants allows both sides to make distinctions about who may and may not be killed; as such, it lies at the core of the protections offered to civilians and other noncombatants in the jus in bello tradition (p. 83). To this mutual recognition, Renic adds the symmetry of harm—that both combatants have to possess the ability to inflict harm on each other for the war to be considered just—and argues that, when it is not present, just war theory cannot be unproblematically applied.
In addition to the challenge they pose to the just war tradition, drones also pose a challenge to the “warrior ethos.” Renic argues that this ethos offers a more narrowly constrained basis for the use of violence in war, but like the just war theory it is premised on the mutual risk of harm. In his fascinating case studies of sniping and aerial bombing, he points out that both innovations were rejected by a number of high-ranking military officers because the reduction in physical risk associated with them violated norms around fairness in wartime. But although it seemed unfair to be able to kill one’s enemy without being at risk, both tactics were eventually normalized. This was not only because the sniper and the pilot could, in principle, be harmed but also because the warrior ethos adapted to encompass values like professionalization, rather than simply reifying individual bravery on the battlefield. To be a professional sniper—or a drone pilot today—is to be bound by codes of appropriate conduct, rather than to conform to the outdated stereotype of the courageous person risking it all on the battlefield. Although one might think that this dynamic of professionalization might allow drone warfare to become normalized, Renic instead argues that the absolute nullification of the threat it promises poses too stark a challenge to the warrior ethos for normalization to take place (pp. 190–91).
Renic’s work represents an important advance on existing work on the ethical foundations of drone warfare and will become an essential reference point for scholars. One of its chief virtues is to articulate the ethical risks that drones present without falling into the trap of insisting that war is only ethical if both sides face direct physical risk. That said, what Renic means by “reciprocal structural risk” could be better clarified. On some level, the logic seems obvious: both sides need to be capable of being harmed. But the stark variations in military capability complicate this picture, especially when strong states and weak states clash. The Persian Gulf War in 1991, for example, featured reciprocal structural risk because both US and Iraqi forces could theoretically be harmed, but the inequality in the actual risk faced by both sides calls into question the claim that structural vulnerability applied. In addition to the fact that structural risk may be more of a sliding scale than a fixed condition, it may be that wars between deeply unequal actors reach the same radical asymmetry that Renic suggests is newly present with drone warfare.
A second challenge to this argument is presented by nuclear weapons. Like sniping, aerial bombing, and drones, nuclear bombs were once a new technology that was widely heralded as changing war. At first glance, they also represent an obvious case of reciprocal structural risk, especially when mutually assured destruction applied, as was the case between the United States and the USSR. But nuclear deterrence extended beyond those cases to states that had no nuclear weapons; for example, allies of either superpower. Nuclear weapons were also considered for tactical use on the battlefield against an enemy that did not possess them. Both of these examples—extended deterrence and tactical use—seem to represent the apogee of the radical asymmetry that Renic describes as novel with drones. As his argument would imply, both uses of nuclear weapons were initially cast as profound challenges to the just war and the warrior ethos, yet notably both were eventually explained, even justified, within these traditions. Thus, it would be useful to extend Renic’s argument and ask why drones, perhaps in a dissimilar way to nuclear weapons, push us beyond the symmetry implicit in the traditional concept of war.
Third, Renic argues that the consequences of the radical asymmetry in warfare are apparent in the expansion of drone strikes to lower-level targets and the dehumanization of those targets (“bug splats”) more generally. In what he calls a “gardener’s vision” of war (pp. 50–51), drones remove terrorists like a gardener removes weeds, but in doing so risk and vulnerability are spread across the civilian population, rather than concentrated in those only defined as enemies. Renic is right to raise this issue because the redirection of risk and vulnerability with drones across actors, including bystanders, has been understudied or even dismissed by advocates of their use. But more controversially he claims that “uneven ratios of military power” may lead nonstate actors to contemplate indiscriminate violence or even war crimes as a way of retaliating (p. 34). This is plausible, but it is hard to assess the causal claim made. Nonstate actors are already risk acceptant and have multiple reasons unrelated to drones to attack soft targets; that they now face radical asymmetry with drones may only add to their motivations rather than alter them. At a minimum, there would need to be more evidence that nonstate actors are choosing indiscriminate violence as way of coping with radical asymmetry to accept this claim as valid.
Finally, Renic’s chief concern is with the US targeted killing campaign, which he argues shows the danger of what happens when a strong power wields the power of drones over the weak. It is worth acknowledging, though, that the US advantage in drones is rapidly eroding as the technology spreads around the world. Today, US military forces abroad are vulnerable to attack with drones, as the Islamic State showed when it deployed commercial drones to attack them in Iraq and Syria. The world is experiencing a diffusion of drones to many new governments and nonstate actors, and their interactions with the technology may not conform to the radical asymmetry that Renic see as inherent in the technology. It may be necessary to assess the ethical implications of drone warfare between combatants with different distributions of power, rather than assuming that radical asymmetry always applies.
Renic’s chief contribution in Asymmetric Killing is to make certain that scholars are attuned to the worrisome ethical consequences of what drones allow the strong to do to the weak. His outstanding book raises urgent questions about justice that are often sidelined in the debate over the effectiveness of drones and other forms of allegedly riskless warfare.
