Response to The Cost of Conflation: Preserving the Dualism of Jus ad Bellum and the Jus in Bello in the Contemporary Law of War.

Thanks to the editors of Yale Journal of International Law and the hosts of Opinio Juris for the opportunity to comment on Rob Sloane’s terrific article, The Cost of Conflation: Preserving the Dualism of Jus ad Bellum and the Jus in Bello in the Contemporary Law of War. The piece is, in my view, essential reading for law of war scholars. I find myself in broad agreement with much of Sloane’s analysis so in my necessarily brief comments I offer a series of questions aimed at clarifying or strengthening his already compelling argument.

1. What is the nature of the dualistic axiom (DA)?. As Sloane points out, DA requires that in bello constraints apply equally to all parties to a conflict. In other words, DA in contemporary international law is a proposition of the jus in bello (or international humanitarian law or IHL)—it is not a structural principle straddling the ad bellum and in bello regimes. The idea is to ensure that no distinctions are made in the rules applicable to each party to a conflict—the irrelevance of the ad bellum justification available to each party is but one instantiation of this more general principle. Nevertheless, this formal equality of belligerents or the formal mutuality of obligations forecloses a certain variety of justification or excuse for acts prohibited by IHL. “Conflation” of, or conceptual overlap between, ad bellum and in bello constraints does not, as such, necessarily pose any deep challenge to IHL. Indeed, the scope and content of some IHL rules are modified, some directly and some indirectly, in their application by reference to ad bellum considerations. For example, POW status arguably does not accord combatant immunity for the crime of aggression (according to the ICRC Commentary on the Geneva Convention for the Protection of Prisoners of War). And whether any situation qualifies as an instance of military occupation within the meaning of Common Article 2 of the Geneva Conventions arguably requires some determination of which party is properly understood as the sovereign over the territory in question. Indirect examples include the fact that IHL imposes less onerous constraints on states when engaged in armed conflict against entities not protected by ad bellum rules. And IHL accords a the privileged postion to members of the armed forces of a state—recognizing a limited right to participate in the hostilities. The relevant IHL rules apply equally to all sides, but the actual application of the rule to some concrete case will, at times, requrie reference to ad bellum considerations. The worry that motivates DA is not a worry about the conceptual integrity of ad bellum and in bello regimes. Rather, the worry is that any assymetry in the obligations assigned the parties to a conflict must be avoided.

2. Is there good evidence that DA is eroding? Sloane, to his credit, points to many concrete examples of “conflation”—which, in his framework, includes examples of conceptual confusion between ad bellum and in bello constraints. But very few of these examples involve actors claiming that the constraints of IHL vary according to the ad bellum justifications (or lack thereof) available to the belligerents. In my view, the troubling examples include only (one reading of) the ICJ opinion on Nuclear Weapons and some of the US rhetoric in the war on terror. I’ll offer no justification of ICJ’s infamously obtuse holding in the Nuclear Weapons case. I will say, though, that the opinion likely provides little reason for serious worry about any erosion of DA particularly since the Court offered no sustained analysis of its seeming conflation of the in bello and ad bellum—and this aspect of the opinion is widely condemned as incoherent at best. The US rheotoric in the war on terror is potentially more troubling, but on closer inspection the US position does not purport to modify IHL constraints by reference to its casus belli. Rather, the US forwarded a construction of IHL that badly misconstrued the material field of application, personal field of application, and substantive content of that law. These claims at times turned on the character of the groups against which the US fights and the nature of the threat posed by such groups, but these points need not turn on—nor are they adequately rebutted by resisting any—erosion of DA. To be sure, claims grounded in some notion of “supreme emergency” may facillitate erosion of DA, but they need not.

3. Why is conflation, even in the limited sense suggested above, problematic? In explaining why dualism is important Sloane emphasizes the institutional rationale—the claim that dualism is necessary because international law has no reliable, effective ad bellum institutional mechanisms that might facillitate a viable aggressor-defender model. Without dualism, war will be prevalent and it will be conducted in an essentially unregulated way because all parties to the conflict will have formally plausible ad bellum justifications warranting relaxed in bello regulation. This rationale is terrifically important, however, over-reliance on it should be avoided. As a practical matter, the institutions in question might be improved—or alternatively, we might think the available institutions work sufficiently well in a non-trivial number of cases. And, as Soane acknowledges in the conclusion, the law of war might need to be reformed in any case to deal with what Sloane suggests are the truly difficult questions. If this is so, the very problem cases Sloane considers as important challenges to DA arguably counsel in favor of reforming the ad bellum machinery rather than tinkering with DA itself—particuarly if we are persuaded that the elimination of war ought be the regulatory priority and we are suspect of any formal equality of belligerents in many contemporary conflicts. In my view, the equality of belligerents (or DA) is also justified because general reciprocity is, as a sociological matter, necessary to ensure compliance with IHL—irrespective of whether any sort of ad bellum regime even exists and irrespective of whether we even have any intuitions about what a just or unjust war might look like.

4. How should we resolve the difficult unanswered questions flagged in the conclusion? Sloane seems to acknowledge, in the end, that some exceptions to DA might be appropriate—but the question is how, given the balance of his analysis, should be even think about the propreity of any such exceptions. This is important, in my view, because the rubber really hits the road on the advisability or acceptability of eroding DA precisely at the points Sloane seem to soften his stance. I sympathize with his position in the paper—that he has no definite answers on the scope or content of any possible exceptions to DA—but I wonder how we might even begin a transnatinal deliberative process regarding any such exceptions.

5. How should we incoporate international human rights law (IHRL) into the analysis of DA—and it’s possible exceptions? applies in time of armed conflict (even if only in the compromised way contemplated in formal derogation schemes) and in this limited sense is part of the full range of in bello constraints. The complication is that ad bellum considerations are ultimately relevant to many questions arising under IHRL. For instance, whether any killing in time of armed conflict is “arbitrary” within the meaning of IHRL surely would require inquiry into whether the attacking party acted in contravention of the ad bellum Same with any determination as to the arbitrariness of any detention in time of armed conflict. (e.g., when Iraq invaded Kuwait in 1990, surely every killing and detention at the hands of the Iraqi forces in Kuwait were arbitrary within the meaning of IHRL. If this is all right, then the scope and content (in the strong sense) varies depending on ad bellum considerations. Perhaps the development of an increasingly robust international law designed to protect human dignity (which includes IHL and IHRL) will inevitably erode DA.

6. Are the ad bellum and in bello proportionality inquiries completely distinct? Sloane is certainly right to say that these inquiries are importantly different, but I wonder whether at times the casus belli exerts important, and perhaps even decisive, influence on the in bello proportionality inquiry. The idea is that ad bellum proportionality should not accord parties unlimited discretion in selecting strategic, operational, and tactical objectives (only to balance the military advantage secured in a discrete operation, determined by reference to these objectives, against the collateral costs imposed on civilians). Instead, in bello proportionality, should understand the ad bellum proportionality constraints, determined by reference to the ad bellum justification advanced by each party, as establishing an outer limit for the legitimate military objectives that concrete operations might further. In this sense, it seems, there is at least one level of generality at which these inquires should overlap.