Monica Hakimi has offered a thought-provoking and timely analysis of how the jus ad bellum operates, placing on the agenda of international legal scholarship a regulatory dynamic that has thus far remained underappreciated. While I believe that a discussion of this dynamic is overdue and thus welcome her plea to take informal regulation seriously, I find some of her underlying assumptions about the nature and function of international law problematic. Therefore, rather than applaud the manifold insightful points Hakimi makes, this essay zeroes in on two related assumptions in her article that I find questionable: first, Hakimi's reasoning about the law-creating effects of informal regulation and, on a related note, the distinction between legality and legitimacy; and second, her tendency to embrace uncritically the particularistic nature of informal regulation. Both points implicate what I term the “hyper-responsiveness” of the law, that is, the (problematic) notion that every momentary political constellation should be reflected in the content of the law. In embracing law's hyper-responsiveness, Hakimi's article sidesteps a discussion of the ambivalent implications of informal regulation.

States sometimes choose to break the law. International lawyers should seek to understand instances of illegality, particularly when they involve the unlawful use of force. But should we also shift our understanding of legality itself in an attempt to bring state conduct within the fold? In particular, what should we make of uses of force that seem to enjoy some degree of international political support while straying from the law governing the resort to force, or the jus ad bellum? Monica Hakimi asks this timely, and indeed timeless, question in her thought-provoking article arguing for a reconceptualization of “The Jus ad Bellum’s Regulatory Form.” Hakimi argues that we must carefully examine state engagement with the UN Security Council, including when it is not authorizing force, to fully understand state behavior. This claim is uncontroversial. However, she also argues that Council activity short of authorizing force can nevertheless establish legality and the Council's “institutional processes can deprive the general standards [that constitute the jus ad bellum] of their legal effect.” The empirical validity and normative desirability of this more provocative claim deserve close interrogation.

In the grand debates of international law, the jus ad bellum is often proclaimed dead, and just as often praised as the “cornerstone” of the contemporary legal order. Both perspectives tend to ignore that the jus ad bellum is not static, but a body of law that states adjust over time. In an important contribution, Monica Hakimi proposes to look at one particular aspect of such adjustment, a concept she frames as “informal regulation” through Security Council action. This essay engages with Hakimi's approach. It inquires whether this approach is as “informal” as Hakimi suggests, and asks whether “informal regulation”—rather than constituting a new category of state activities to study—is not already part of conventional approaches to the jus ad bellum. Proceeding from Hakimi's analysis, the comment assesses whether there is room for “informal regulation” beyond the Security Council.

Monica Hakimi's article probes the legal significance of an interesting phenomenon: the UN Security Council condoning the use of force, as opposed to authorizing it. She offers an innovative perspective on this little-studied dimension of how the Council contributes to the development of jus ad bellum. While I applaud much in the article, I question her characterization of what the Council is condoning in the cases she reviews. She claims these are “fact-specific decisions,” whereas I argue that the Council is endorsing controversial interpretations of the law on the use of force. This disagreement does not detract from Hakimi's observations about the policy implications of the practice, or about the Council's role as a site for deliberation and argumentation about the content of international law. But it does cast doubt on her conceptual claim that there are two distinct “regulatory forms,” which together provide the content of jus ad bellum, one particularistic and procedural, the other general and substantive. All legal claims and justifications entail the application of general standards to particular facts, either explicitly or implicitly. Most of her case studies can be explained in those terms. Thus, while the Council's practice of condoning the use of force is important to understand, the “conventional account” she derides provides a more persuasive and parsimonious explanation of that phenomenon.