Kaoru Obata (chapter 14) argues that the present-day Global Constitutionalism and its non-hierarchical character often presuppose the validity of the principle of “functional complementarity”. This principle means coordinating national and international jurisdictions according to their procedural effectiveness in providing redress. It seems to have been established in Europe, mainly in EU law and the European Convention on Human Rights. It entails, however, an unsolved problem in its antithetical functioning for “core” and “peripheral” members. Obata also casts doubt on its universal applicability through analysing the jurisdictional immunity of international organizations as well as the theory and practice of admissibility before the International Criminal Court. The principle is felt not to be sufficiently valid in relation to unreliable jurisdictions mainly in Africa and Asia. The arguments for exclusive jurisdiction over the UN’s own peace operations or original jurisdiction of the international community over “core crimes” sometimes rule out any applicability of the principle. Obata analyses whether given these actual limitations of the principle of functional complementarity the global constitution, even in its pluralistic version, will not work coherently and harmoniously.