Privileging Asymmetric Warfare (Part ll)?: The 'Proportionality' Principle Under International Humanitarian Law

The laws of war are undergoing a fundamental transformation. The first step was the unmooring of the obligations of states and armies from the binds of reciprocity - the prospect that violations should be avoided because they will result in comparable reprisals from the other side - that began with the Geneva Conventions of 1949 and culminated in the 1977 Additional Protocols (AP I and II). The second major step - still an ongoing process - has been to substitute for the threat of reprisals the grounding of these obligations in enforceable, positive law. What started haltingly with the promulgation of several “grave” offenses in Geneva has - with the establishment of the International Criminal Court, international criminal tribunals for the former Yugoslavia and Rwanda authorized by the UN Security Council, conventions against torture and other practices, and the sustained pressure of a proliferating number of nongovernmental organizations seeking to enforce human and IHL rights violations through international criminal and tort law - reshaped the international legal landscape. These developments call for closer attention to AP I, the principal legal framework for regulating warfare that many writers on international law believe binds not only ratifying countries, but also all nations and their inhabitants as a matter of customary international law. In an earlier article in this journal, I argued that the growth of “guerrilla” or irregular warfare - involving non-state armed groups locating themselves within dense civilian settlements in order to provoke a military response from occupying or NATO armies that would inevitably cause civilian casualties and generate additional recruits for the insurgent cause - requires a greater emphasis on broadly defining and strongly enforcing the duties of defenders to refrain from locating their military forces and assets among civilians. The overarching objective of IHL is to reduce unnecessary harm to civilians in the armed conflicts that warfare causes. This risk of harm is a joint product of both defenders and attackers and has to be regulated as such. The focus of this article is on the so-called principle of “proportionality,” which regulates the conduct of warfare in an effort to limit harm to civilians during otherwise legitimate armed conflict. I use the qualifying adjective “so-called” because “proportionality” in this context is a misnomer. The actual obligation, as set forth in Articles 51(5)(b) and 57(2)(b) of AP I, speaks in terms of prohibiting (and deferring) attacks expected to cause incidental civilian losses “which would be excessive in relation to the concrete and direct military advantage anticipated.” Neither the text nor the policy of IHL requires some form of “balancing” or use of a “sliding scale” to ensure that the military objective is “proportionate,” in the sense of being commensurate with the extent of civilian losses? What is required is that the military use no more force than necessary to accomplish concrete, direct military objectives. The proposed “excessive loss” formulation is not only truer to the text of AP I but provides a sounder, more principled basis for judging violations, for insisting on military commander compliance - than the more elastic, manipulable “proportionality” formulation, which invites commentators and tribunals to second-guess military objectives and compare and weigh essentially non-comparable factors.