The Legal Basis of “Evolutionary Interpretation” in the WTO Dispute Settlement

In Shrimp‐Turtle, the WTO Appellate Body interpreted the term in GATT Art. XX(g), “natural exhaustible resources” with “evolutionary approach.” The question that this paper purports to answer is whether such “evolutionary interpretation” is permitted under the DSU Art. 3.2, and especially in light of US‐Gasoline, in which the AB laid out two starting points for the interpretation of WTO Agreements: i) that it should be interpreted in accordance with Articles 31 of the VCLT, and ii) that it should not be interpreted in clinical isolation from public international law. The paper shows that the evolutionary interpretation is one of many of treaty interpretative techniques that have sound legal basis in the public international law but had nonetheless been left out of the VCLT, and thus, it should be available for the AB to use by virtue of the second prong of Gasoline. Further, this paper suggests three criteria that should be met for the evolutionary interpretation to be allowed: 1) when the terms used have or are acquiring an evolving meaning in general international law, 2) when language used in expressing the object and purpose of a treaty to show a recognition or intention for the treaty to be able to have a progressive development, and 3) when the description of obligation is expressed in broad terms.