This book proposes a decolonial deconstruction of the interdisciplinary study of International Law (IL) and International Relations (IR). In so doing, it aims to satisfy some specific needs. First, it aims to provide an original, authorial book on the interdisciplinary study of IL and IR, and on the politics of international law, which is critical, politico-philosophical, and (meta)theoretically oriented, written by someone from a singular-plural spatiotemporal position in the global south. Second, it aims to offer an interdisciplinary study much inspired by critical IL theory, critical IR theory, deconstruction, postcolonial, and decolonial thoughts. Third, it aims to give centre stage to?the international?supplement, and its ontopolitical difference. Fourth, it aims to rethink the relation and differentiation between the international and the world, provincializing the former while de-anchoring the latter. Fifth, it aims to rethink the politics of international law and reimagine the interdisciplinary study of IL and IR before the and of the world, that is, before the singular-plural, hauntological movement of a différant and pluriversal world of many worlds.