Has the Fair and Equitable Treatment Standard Become a Rule of Customary International Law?

Abstract

This article examines whether or not the FET standard has become a rule of customary international law. The article contains the first empirical analysis of this question based on the two conditions under which a treaty-based norm can transform into a customary rule. The article will argue that the standard has not become a rule of custom. While the practice of States to include FET clauses in their BITs can be considered as general, widespread and representative, it is not uniform and consistent. There are in fact many different types of FET clauses and these variations matter a great deal. Also, the practice of States outside treaties shows that they rarely offer FET protection to foreign investors under their foreign investment laws. There is no indication that States parties to BITs believe that they have an obligation (opinio juris) under international law to provide FET protection to each other’s investors.