Does Who Matter? The Various Forms of Authority to Use Military Force

Abstract

In this article, I will ask what authority means under international law. I will find that there are various actors with different forms of authority, but no overarching concept of what characteristic it is that may endow an actor with authority, and even less of a coherent conception of legitimacy as a requirement for such authority. In fact, international law recognizes different authorities for different causes and different contexts, allocated to different actors, who base their authority on different characteristics (state legitimacy, representativity, military power, control). There is a range of possible consequences that may follow from having authority (i.e. the concept of authority in the sense of “power” can be disaggregated) and there are a range of different kinds of actors might be differently able to trigger these various consequences (i.e. authority as an attribute of an actor can be also disaggregated). For instance, under the jus in bello, non-state actors can create a state of armed conflict, in which they can often – but not always -- continue to use military means without legal sanction. Hence, by resorting to arms, a non-state actor can arrogate for itself the right to further use military means. While the jus ad bellum may still, in principle require legitimacy (in the quite formal sense of being a state), current jus in bello covers also non-state actors, and from a practical point of view, the jus in bello regulation undermines any jus ad bellum requirement of legitimate authority.