The collective security system and the enforcement of international law

After a few brief terminological remarks on the concepts of enforcement, coercion and sanction, this chapter will briefly recall the theoretical debates about the role of enforcement in our understanding of international law. A few observations will then be formulated as to how the creation of a collective security system regulating the use of force, irrespective of its actual enforcement function, came to upend the way in which enforcement of international law is understood by international lawyers. Taking into account recent developments pertaining to non-state actors, as well as targeted and smart sanctions, it will reevaluate the coercive role that can be performed by the collective security system. Finally, this chapter will explain how the various steps in the development of the collective security system and our understanding thereof directly impinge on how international law as a whole is perceived. The concluding remarks will invite some critical reflections on the need of a catharsis that will purge international lawyers’ "enforcement obsession" vis-à-vis their reading of the collective security system.