Standards of Appellate Review in International Dispute Settlement Current Use and Conceptual Challenges

A recurrent challenge in the design of appellate mechanisms in international dispute settlement is how to enable meaningful supervision while preventing a complete repetition of proceedings. This article assesses the use of standards of review as a tool to restrain appellate review. It discusses the standards applied in the WTO, the ICJ, and a potential future investor-state appeals tribunal. The article finds that restrictive standards of review are not frequently used in second-tier mechanisms of international dispute settlement, and identifies two reasons for this absence. First, restrictive standards of review may interfere with the appellate reviewer’s objective of ensuring consistency among first-instance decisions. In addition, standards of review rarely provide clear benchmarks indicating when an appellate reviewer should overturn a decision. This may increase the complexity of second-tier proceedings as parties will engage in preliminary debates about the correct interpretation and application of the standard of review.