Uniformity Versus Specialisation: A Uniform Regime of Treaty Interpretation?

Fragmentation of international law can occur at two levels: at the level of substantive rules (applicable law), and, at the level of interpretive method. Whereas the substantive aspect of fragmentation has spawned an enormous literature over the last decade, interpretive fragmentation has received less attention. The focus of this chapter is on this second dimension: does international law know a single, unified method, or equivalently, regime or approach to treaty interpretation? Articles 31-33 VCLT purport to set out a unified approach to interpretation. Yet this chapter contends that the VCLT constrains treaty interpreters only on the margins, and that varieties of treaty interpretation lurk behind the veneer of the VCLT’s general interpretive framework. On closer inspection, interpretive practices in international law diverge, just like in national law. The emergence of specialised interpretive methodologies in international law mirrors the earlier development of statutory and contract varieties of interpretation in domestic law.