THE ARMED ATTACK EXCEPTION TO NEUTRALITY IN INTERNATIONAL PEACE AND SECURITY LAW

Abstract This article argues that the scope of the neutrality duties of non-assistance and prevention allows for an exception – a carve-out for assistance given to the victim State of an armed attack. Rather than weighing in on debates as to whether current State practice accepted as law suffices to establish this rule inductively, the article offers a different approach to grounding the argument for this exception in the methodology of the sources of international law, which thus far has been underexplored. The central argument of the article is that the exception or carve-out—and its contours—deductively flows from the structure of international law of peace and security and, in particular, the victim State's right to self-defence. The purpose of that right—enabling the effective termination of the armed attack—must not be undermined through prohibitions of military assistance and duties of prevention. These considerations define the scope of neutrality duties as revealed through systemic treaty interpretation. Such deductive reasoning equally determines the scope of customary neutrality duties, whether discerning that scope is framed as systemic interpretation or as identification of custom.