Grounds for the application of international rules of interpretation in national courts

Interpretative practices between legal systems and domestic courts vary widely. This inevitably will affect the interpretation of rules of international law by domestic courts. The question is whether there are good grounds for national courts to limit divergence of interpretations, by relying on international principles of interpretation. This paper explores three possible grounds on the basis of which domestic courts can resort to an application of international rules of interpretation: the effective performance of treaty obligations, the international quality of domesticated norms, and the external authority of decisions of domestic courts. The paper argues that, depending on the context, each of these grounds may offer a justification for relying on international rules of interpretation, but that competing considerations may pull in diverging directions, and that the international rules of treaty interpretation do not necessarily preclude this.