Treaties establishing objective regimes

The issue of treaties establishing objective regimes has been neglected by the Vienna Convention on the Law of Treaties. Building on the principle of relativity of treaties, the Convention only deals with the effects of specific treaty rules on third states. This chapter argues that third states never acquire the same status of states parties, even when they consent to the specific treaty rules that affect them. Analysing the significance of treaties establishing objective regimes under general international law, it clarifies that such treaties may affect third states even when they do not embody rules of customary law. Due to the relevance for the international legal order of the unique erga omnes regime created by the treaty, the situation regulated by it can no longer fall within the scope of the absolute 'freedom' previously accorded to third states.