Chapter

The process of custom formation in contemporary international law

Georges Abi-Saab

Proceedings of the conference on customary international humanitarian law

[Tehran] : [Majd publications], [2009?]

p. 105-115

English

Until 1945, custom was considered as the main source of international law. However, after the Second World War, there was a growing feeling that the process introduced in article 13 of the Charter of the United Nations - described as "the progressive development of international law and its codification" - somehow pushed custom to backstage. This process, embodied particularly by the International Law Commission, allowed the preparation of codification conventions. Paradoxically, however, this impression was reversed and a resurgence of custom appeared on the horizon in 1969 when the International Court of Justice had to answer the question whether article 6 of the Geneva Convention on the Continental Shelf of 1958 had become part of customary international law and could be applied to Germany who had ratified the Convention. The Court concluded that codification treaties can have three possible and different types of effect on custom : a declaratory effect, a crystallizing effect and a generating effect. This doctrinal presentation slowly became the conventional wisdom about the relationship between codification treaties and customary international law. The author compares this custom, which results from, or spins around the process of codification and progressive development, and compares it with the old custom of the nineteenth century up to the Second World War, and sees if we are really speaking of the same legal phenomenon, of the same process.

• Proceedings of the conference on customary international humanitarian law / created by: Pouria Askary, Jean-Marie Henckaerts