North Sea Continental Shelf cases: ICJ 1969

The court described the process by which a treaty rule may become a rule of customary law: ‘It would in the first place be necessary that the provisions concerned should, at all events potentially, be of a fundamentally norm-creating character such as could be regarded as forming the basis of a general rule of law . . With respect to the other elements usually regarded as necessary before a conventional rule can be considered to have become a general rule of international law, it might be that, even without the passage of any considerable period of time, a very widespread and representative participation in the convention might suffice of itself, provided it included that of States whose interests were specially affected. . .
Although the passage of only a short period of time is not necessarily, or of itself, a bar to the formation of a new rule of customary international taw on the basis of what was originally a purely conventional rule, an indispensable requirement would be that within the period in question, short though it may be, State practice, including that of States whose interests are specially affected, should have been both extensive and virtually uniform in the sense of the provision invoked; – and should moreover have occurred in such a way as to show a general recognition that a rule of law or legal obligation is involved.’


[1969] ICJ Rep. 3

Cited by:

CitedMohamed, Regina (on the Application of) v Secretary of State for Foreign and Commonwealth Affairs (No 1) Admn 21-Aug-2008
The claimant had been detained by the US in Guantanamo Bay suspected of terrorist involvement. He sought to support his defence documents from the respondent which showed that the evidence to be relied on in the US courts had been obtained by . .
Lists of cited by and citing cases may be incomplete.


Updated: 15 May 2022; Ref: scu.272828