The NAFTA arbitral award on Canadian Cattlemen is specific in having its entire reasoning based on principles of treaty interpretation. Attempting to clarify the notion of “investment” under the NAFTA Agreement, this award carefully examines every principle of interpretation recognized under the Vienna Convention on the Law of Treaties that is applicable to the case. This article analyses the tribunal’s use of the methods of interpretation such as plain and ordinary meaning, object and purpose, context, subsequent practice and of supplementary means of interpretation. In terms of supplementary methods of interpretation, the tribunal’s reference to previous arbitral awards as supplementary means of treaty interpretation is evaluated, especially against the background of the lack of precedential force of international arbitral awards.
Journal of International Arbitration