In his paper, Professor Pauwelyn argues that pursuant to Article 31(3)(c) of the Vienna Convention on the Law of Treaties (Vienna Convention), the Appellate Body should consider other rules of international law in the interpretation of the WTO Agreements, when that law reflects the "common intentions" of the parties to the WTO. He argues that this does not mean that "all the parties to the WTO treaty must have formally and explicitly agreed, one after the other, to the new non-WTO rule; nor even that this rule must be otherwise legally bind all WTO members; but rather, that this new rule can be said to be at least implicitly accepted or tolerated by all WTO members, in the sense that it can reasonably be considered to express the common intentions or understanding of all members as to the meaning of the WTO term concerned.”
Interpreting the WTO Agreements- A Commentary on Professor Pauwelyn's Approach,
Mich. J. Int'l L.
Available at: https://repository.law.umich.edu/mjil/vol25/iss4/7