Successive ICJ Presidents have expressed concern about the proliferation of international tribunals and substantive fragmentation of international law. This is not a new phenomenon. International law has always lacked a clear normative and institutional hierarchy. The problem is more how new institutions have used international law to further new interests, especially those not predominant in traditional law. The anxiety among ICJ judges should be seen less as a concern for abstract “coherence” than a worry about the demise of traditional principles of diplomatic law and the Court's privileged role as their foremost representative. As jurisdictional conflicts reflect divergent political priorities, it is unclear that administrative co-ordination can eliminate them. This does not, however, warrant excessive worries over fragmentation; it is an institutional expression of political pluralism internationally.

In his opening lecture of the LL.M. Program in Public International Law at Leiden University, Judge Buergenthal examines whether the recent phenomenon of the proliferation of international tribunals is to be welcomed or regretted by those who are interested in seeing international law become a vibrant and politically relevant legal system. He addresses questions relating to their interaction and the delimitation of their respective roles.