The first part of this blog post commended the self-restraint of the ILC Special Rapporteur on the identification of customary international law. It simultaneously argued that the work of the ILC, somewhat paradoxically, laid bare a formidable emancipatory fervour at play outside the Palais des Nations. It is as if the intellectual prison of custom was gradually being turned into a large dance floor where (almost) everything goes. The following observations substantiate that claim and shed light on some of the consequences of this ongoing revelling.
Hunting (and finding) practice everywhere
It has long been accepted that the myth of induction in the theory of customary international law was more difficult to uphold in relation to opinio juris. This is why the subjective element has always been the object of the most severe criticisms or reservations. Yet, international legal scholars have started to realise that the myth of induction is not less difficult to vindicate in connection to the objective element, i.e. practice. As the Nicaragua decision famously taught us, how can one possibly ascertain the unascertainable, that is an intangible practice of abstention? Since the great majority of rules of international law are of a prohibitive character, the establishment of customary international law very often requires a speculative venture into nothingness. Confronted with this overdue realisation that practice – especially with respect to prohibitive rules – was not more easily captured inductively than opinio juris, international lawyers have been forced to resort to all new sorts of nets and traps to hunt and capture practice where there was none.