Indeterminacy in the Law of Armed Conflict

Abstract

If a “fog of law” has settled over contemporary armed conflict, how might we find our way through it? It seems there is no rule of the law of armed conflict whose content or application is not disputed by distinguished scholars or experienced practitioners. These disputes may arise from the ambiguity or vagueness of some rules, the incompleteness of others, or inconsistencies between different rules. It does not help matters that general problems with the identification and application of customary international law are magnified with respect to the customary law of armed conflict.

Legal indeterminacy, in its different forms, might be reduced or resolved in light of the object and purpose of the law of armed conflict, or by taking into account other relevant rules of international law. Unfortunately, the object and purpose of the law of armed conflict is itself the subject of deep disagreement. So is the relationship between the law of armed conflict and other branches of international law, most notably the law of inter-State force and human rights law. Most corrosively of all, some are quick to denounce purposive interpretation of existing law as covertly proposing new law and systemic integration as conflation or corruption. If this atmosphere persists, the fog of law may never lift.

One aim of this article is simply to map these forms of legal indeterminacy — ambiguity, vagueness, incompleteness, and inconsistency — and the different legal techniques available to address each of them, using concrete controversies to illustrate abstract ideas. A second aim is to clear up some misunderstandings regarding the object and purpose of the law of armed conflict, as well as its relationship with other rules of international law. The purpose of the law is not to balance a constraining principle of humanity against an authorizing principle of military necessity. Instead, the purpose of the law is simply to protect persons and objects to the greatest extent practically possible, that is, without depriving other rules of international law, which authorize certain uses of armed force, of practical effect. These clarifications may improve purposive interpretation of the law of armed conflict and, perhaps, make the field safe for systemic integration once more. A final aim is to suggest that the law of armed conflict contains a number of clues for its own interpretation, some of them hidden in plain sight, including a recurring pattern of general protections with limited exceptions.

Keywords: ambiguity, vagueness, systemic integration, purposive interpretation, law of armed conflict, international humanitarian law, proportionality, civilian, combatant, precautions, distinction, doubt, verification