William A. Kerr, Stuart Smyth, Peter W.B. Phillips, and Martin Phillipson
University of Saskatchewan, Canada

The Vienna Convention on the Law of Treaties was designed to provide guidance regarding the legality of primacy between international agreements. Article 30 of the Convention states that when one party to a previous treaty is not a party to a subsequent treaty, then, “the earlier treaty only applies to the extent that its provisions are compatible with those of the latter treaty.” To date, the implications of this have not been well explored with respect to the World Trade Organization (WTO) Agreements and the Cartagena Protocol on Biosafety (CPB). Given that three of the top five producers of genetically modified crops (Argentina, Canada, and the United States) are not signatories to the CPB, this issue could become contentious. This article provides a detailed assessment of the applicability of the Vienna Convention to the WTO and the CPB. The resulting policy implications and potential trade concerns are highlighted and addressed. The results suggest that formal international law has little to offer in terms of determining which institution—the CPB or the WTO—should take precedent in the case of a dispute. Given that most major exporters of GM crops do not belong to the CPB, but most states (both potential importers and exporters) belong to the WTO, the latter should be the venue where disputes are adjudicated. A WTO panel would likely not consider socio-economic concerns as an acceptable justification for the imposition of trade barriers.

Key words: Cartagena Protocol on Biosafety, genetically modified crops, international law, Vienna Convention, World Trade Organization.