Islamic State of Iraq and al-Sham (ISIS) as an Aggressor in International Law : Defining Aggression post-13/11

Article 42.7 TEU, invoked by France, binds EU member states and creates an obligation upon them to provide aid and assistance by all available means to a state victim of an “armed aggression”. This could be a decisive moment which might finally award the capacity to be an aggressor to non-state actors, as EU law refers to international law for the determination of what constitutes an ‘armed aggression’. Indeed, this thesis will answer the question of whether ISIS can be defined as an aggressor for ordering the Paris attacks by arguing a reconceptualization of aggression as inclusive of acts by non-state actors. The two relevant concepts of international law are ‘aggression’ and ‘armed attack’. Although the International Court of Justice (ICJ) found that an armed attack amounts to an act of aggression, these two correlative notions are not developing simultaneously nor coherently. Indeed, aggression is construed within the traditional paradigm of an international law limited to interstate relations. Aggression is commonly defined as a “State conduct that either initiates war against another State or brings about a situation in which the victim is (or may be) driven to war”. Thus, aggression cannot be legally considered outside of the context of interstate war and/or unlawful use of force by states. To the contrary, the required attributability of an ‘armed attack’ to a state not only has been widely discussed, but the evolving state practice tends towards the possibility for an armed attack to emanate from a non-state actor. Therefore, since aggression and armed attack are really two sides of the same coin and the concepts are synonymous, I argue that, as the interpretation of armed attack has been re-construed to include acts by non-state actors, aggression should follow a similar development. Such re-interpretation of aggression is not only feasible but also necessary. Indeed, there is no irrefutable legal presumption or rule that would justify a rigid interpretation of aggression. Not to mention that actually constraining aggression to a state’s behavior is incompatible with the very raison d’être behind the prohibition of use of force and the prohibition of aggression. Although ISIS might appear as a generic terrorist organization, it is truly a sui generi case, which simultaneously marks a point of no return in the development of global terrorist jihadism. Moreover, it exposed the challenges and inconsistencies of international law. Indeed, despite its controversial state-building capacity, it cannot be recognized as legitimate since territory cannot be acquired by aggressive use of force. Concomitantly, a traditional and rigid interpretation of aggression disapproves the recognition of ISIS as an aggressor precisely because of the lack of statehood. As the determination of the content of the law is affected by external factors, law might remain relevant without resorting to new normative texts by a simple conceptual change. Therefore, I will build upon the indeterminacy of law, as I attempt to argue for a new interpretation of aggression, encompassing the acts by non-state actors