Which international obligations are characterised as obligations owed erga omnes or erga omnes partes is today a crucial question for the enforcement of international law, particularly through adjudication before the International Court of Justice (ICJ). The ICJ, however, has not given sufficiently clear indication as to how it understands and identifies obligations erga omnes and erga omnes partes. This lack of clarity and consistency permits varied approaches to the articulation of such obligations, ultimately leaving uncertain the enforceability, through adjudication and otherwise, of a wide variety of obligations.