De Visscher, Paul Keywords: Treaties | Constitutional law | International law and domestic law | Mots clefs: Traités | Droit constitutionnel | Droit international et droit interne | ABSTRACT Whether we want to see in actual practice the first manifestations of an international constitutional law or want to see in international law "national law for external use", it is clear today that internationalists can no longer ignore evolution. In this course, Paul De Visscher focuses on the most recent trends in the phenomenon of ha…