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Guest Post: The ILC Project on the Identification of Customary International Law–Saving the Temple from Submergence

[Duncan French is the Head of Law School and a Professor of International Law at the University of Lincoln and Jean d’Aspremont is a Professor of International Law at the University of Manchester and a Professor of International Legal Theory at the University of Amsterdam.] The two-day expert seminar on the identification of customary international law, co-organised by Lincoln Law School and the Manchester International Law Centre, took place on 13-14th November at the University of Lincoln. With the active participation of Sir Michael Wood, the Special Rapporteur of the International Law Commission (hereafter ILC) on the issue, the seminar witnessed the contribution of over 25 international lawyers from around the United Kingdom. Discussions focused on Sir Michael's second report, the eight draft conclusions adopted by the ILC drafting committee and those issues yet to be considered in the preparation of the third report. A blog for Opinio Juris in advance of the seminar entitled “Amidst the Academic Mania for the Identification of Customary International Law–The ILC and the Operative Value of Distinctions” had flagged many of the salient matters discussed during the seminar. As could be anticipated, interventions were made on the methodological aspects of the "two element" approach to the identification of customary international law, the role of international organizations in the determination of customary international law, inaction and acquiescence, and how customary international law has developed within particular areas of international law, notably in the economic and environmental spheres. There was also more wide-ranging discussion on, inter alia, the notion of opinio juris, the scope of the ILC conclusions, whether the development of human rights has impacted upon the identification of customary international law, international organizations, non-state actors, the role of the persistent objector, the relevance of specially affected states, the temporal inter-relationship between state practice and opinio juris, and the existence of special/local/regional custom, etc. It is beyond the purpose of this blog to revisit the depth and richness of these exchanges. It will limit itself to formulating four sets of remarks. First, there was general agreement among the participants that the scope of the ILC codification exercise is rightly restricted to the identification of customary international law. This was perceived as a pragmatic, and reasonable, delimitation. Nevertheless, it was acknowledged that one could not always easily distinguish between the formation, the identification and the evidence of customary international law. In that sense, it was highlighted that the current title was too narrow, and that, in the French text, the word (‘détermination’) captured more accurately the more nuanced and various complexities of the question. And this was not the only issue arising in the respective translations. The importance - both conceptually and practically - in the assessment of evidence in identifying customary international law [draft conclusion 3] takes on a subtly alternative understanding when interpreted as ‘áppreciation des moyens’. Secondly, as indicated in the earlier blog, the practice and opinio juris of international organizations in the identification of customary international law - as distinct from the acts of States within and through such organizations - proved particularly contentious and triggered a lot of debate. The contribution of international organizations primarily raises the question as to whether the practice and opinio juris of international organizations should contribute generally to any customary rule, or only when it concerns the development of rules that will also bind international organizations. The Special Rapporteur and several participants indicated that, in their view, an organization can only contribute to the formation of a rule of customary law which it can potentially be bound by. This has to do with the self-commitment at the heart of the doctrine of customary international aw. It is also perhaps as a matter of equity between participants in the international legal system. Equally, there was discussion as to which international organizations can contribute to the formation of customary international law. Legal personality is a seemingly determinate variable. Yet, a question remains as to whether there is a significant difference between organizations with a high degree of autonomy, those with more independent-minded secretariats and those international organizations that are member-state driven. It seems axiomatic that the greater the autonomy, the greater the extent to which the practice and the opinio juris of an international organization itself (in contrast to the acts of its members within the context of the organization) should contribute to customary international law. The point was also made