Thomas Weatherall (Georgetown University) has posted Against Fragmentation: International Common Law and the Development of Jus Cogens on SSRN. Here is the abstract:
Approaching jus cogens as a form of international common law provides a process-based backstop against fragmentation within jus cogens by reinforcing the common legal space within which courts and tribunals operate. To that end, this paper focuses on the role of international courts and tribunals in developing jus cogens as a kind of international common law. In the first section, I introduce the concept of common law and discuss its applicability to international law and jus cogens in particular. Next, I consider the practicability of this application by demonstrating capacities in which international courts and tribunals operate like common law courts vis-à-vis jus cogens. Finally, I assess the role of precedent in international law and how precedent might support a common law approach to jus cogens.