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

by Duncan French and Jean d'Aspremont

[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 that the contributions of international organizations to customary international law raise difficult questions of attribution which should not be overlooked. Indeed, the practice (and opinio juris) witnessed within the framework of an international organization can be constitutive of the individual practice (and opinio juris) of each of the member states having supported it, of all the member states of the organization collectively, of the organization itself, or of all of them at the same time. Depending on whom the practice and opinio juris are attributed to, questions of identification of customary international law ought to be approached differently.

In connection with international organizations, mention was made of the possibility that statements of international organizations may not necessarily be practice or opinio juris but, more simply, authoritative interpretations of existing rules (on this point, see here). This possibility presupposes that the ILC upholds the distinction between the establishment of the rule and the determination of the content which constitute two – albeit intertwined – distinct processes.

Thirdly, it was noted that the ILC drafting committee had removed the textual reference in the draft conclusions to having due regard to the practice of specially affected states, notwithstanding a reasonably settled jurisprudence on the matter. Of course, there was a risk that specially affected states might accord with the most influential, most dominant states, if not more directly the P5. But equally, specially affected states might well afford assurance to other states, and there certainly is no a priori justification for the selective application to only some states. In any case, the notion seemed to warrant greater care and should be addressed more explicitly either in the conclusions or in the commentaries.

Similar arguments came to the fore as regards the persistent objector “rule”. Whereas experience highlights examples where the US and the UK have, for instance, sought to benefit from being a persistent objector, it is a rule that has the potential to be used by a much broader range of states. There was, in addition, some discussion as to the value of the retention of the persistent objector rule – recognising that in almost every instance, the reliance on the rule is temporary. Nevertheless, as a strategic measure available to states, it was felt less problematic to include it, so long as the conditions for its application were sufficiently stringent.

Fourthly, though all participants (but one) felt the dichotomy between physical versus verbal acts (where the former only counted as state practice) could no longer be upheld, there remained genuine considerations concerning the value, weight and content of verbal acts, recognising that “verbal” acts very often included documentary and other written forms of practice. This was not just a dispute over the potential risk of double-counting of verbal acts (ie the same evidence counting simultaneously as both practice and opinio juris) but that, in more subtle form, such acts might evidence custom that was ultimately not substantiated in the real activity of states. Of course, the requirement for widespread and consistency in practice mitigates against this risk to a significant extent.

This being said, an over-reliance on verbal acts risks the generation of rules of customary international law which – rather than being accompanied by opinio juris (“accepted as law”) – exist because they are viewed sive necessitatis (“as considered necessary”). This is, of course, neither lex lata nor where many of us would want to see customary international law develop. Nevertheless – combining that with the declaratory nature of some judgments of the International Court in the finding of customary international law – this formation of custom sive necessitatis is perhaps closer than many of us are prepared to admit.

The two-day seminar at the University of Lincoln took place whilst the robotic probe, Philae, landed on – and began to investigate – Comet 67P. There is however another Philae, which has perhaps more pertinence to the topic under review. This Philae was an Egyptian island of historic temples that was increasingly lost under the rising waters of the River Nile during the twentieth century – though fortunately the riches were saved for posterity. The work of the ILC Special Rapporteur is at a crucial point. The potential value of his conclusions on the identification of customary international law to the international and domestic legal communities – courts, counsel and government officials – is significant. However, there remains a risk of being submerged by both unrealistic expectations and the overwhelming tide of legal complexities and political questions that the issue of the identification of customary international law invariably prompts. As the debate in Lincoln made clear, avoiding such a fatal submergence calls for a strict delineation of the project and the upholding of some crucial and fundamental distinctions. The Special Rapporteur must certainly be commended for his awareness of such pitfalls. It is hoped that he will be followed by the ILC.

A follow-up meeting will most likely be organised in Manchester in 2015.

2 Responses

  1. I agree that the situation of international organizations within the customary law construct is interesting. However, I would think that acts of international organizations are better characterized as interpretations of international law and not customary international. If you view customary international law from a consent theory approach, allowing an international organization to contribute to customary international law would take away state practice especially when some international organizations require less than a consensus when adopting a resolution or rule. Even if you were to argue that a state has consented to the organization and that method for adopting rules, by dissenting in a vote, a state is effectively withdrawing its state practice or opinio juris for purposes of being bound by customary international law even if it will still be bound by the organization. Also, there seem to be many problems with how the practice of an international organization will be characterized. Although reaching a specific number of states is not necessary for a norm to become customary international law, could the practice of a single organization be considered the practice of multiple states within that organization? Also, would the persistent objector doctrine be considered if states within the organization vote against adopting a norm?

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