International governance is increasingly characterized by the decline of formal intergovernmental organizations as the preferred sites of rule-making, as the growth rate of intergovernmental organization has declined by 20 per cent since the beginning of the twenty-first century.1 More than a decade after the debates about fragmentation2 and regime-collision in international law,3 it now seems clear that the key question is not that, as a professional experience, international law seems divided in sometimes incoherent specialized regimes, but that international lawyers have a more dense and diverse institutional landscape to deal with.