How to Win a WTO Dispute Based on Non-WTO Law? Comments on Joost Pauwelyn’s Paper

The following comments concentrate on the areas of disagreement in the positions of Joost Pauwelyn on the one side and Gabrielle Marceau and Anastasios Tomazos on the other. As Joost Pauwelyn and Gabrielle Marceau are two of the main proponents in the debate on the relationship between international law and the WTO system, in dealing with their views one has to address several of the core issues raised in this discussion so far. In order to better understand these issues and the respective positions presented, it appears appropriate to take some of their earlier writings into perspective. Joost Pauwelyn's position can be summarized quite succinctly. According to him, one has to distinguish jurisdiction and applicable law. Against this background, he argues first that a panel's jurisdiction can be taken away through international agreements that do not form part of WTO law. Similarly, Pauwelyn submits that substantive rules of international law conflicting with WTO law can be invoked as a defence even within WTO proceedings. Both contingencies depend on the principles of international law, in particular Articles 41 and 30 of the Vienna Convention. Underlying Pauwelyn's approach is a wide definition of conflict. Although not extensively addressed by Pauwelyn in his present paper, Marceau and Tomazos deal with this fundamental issue in more detail. According to Pauwelyn, explicit permissions to restrict trade in other treaties may prevail over WTO law, depending on the rules of international law. Importantly, it follows that Article XX of the GATT and other WTO exceptions, WTO provisions incorporating non-WTO norms by reference, and waivers are not the unique or primary links to non-WTO international law: a WTO Member which is required or permitted to restrict trade by a non-WTO treaty need not comply with clauses like Article XX (and need not employ the least trade-restrictive means e.g. under Article XX(b)), if WTO law is superseded by a given non-WTO treaty.