Originally from Dispute Resolution Journal

This article analyzes the legal standing of amici curiae in international trade and investment arbitration. Drawing on the most important decisions by the WTO Appellate Body and arbitral panels, the article emphasizes the fundamental tension between the traditional consent-based foundation of arbitration and the increasing need for transparency in proceedings that affect the public.

In the last several years, the idea that international investment arbitration should become more transparent has gained wide acceptance. Until quite recently, however, disputes between States and foreign investors were considered private as a matter of law. The main implication of this approach was the secrecy of the proceedings. While this paradigm is still dominant in the field of international commercial arbitration, it has been substantially weakened in the area of investor-state arbitration.1 It is now commonplace to make arbitral awards and/or other parts of the proceedings public. This is perfectly consistent with the subject matter of investor-state disputes, which in virtually all cases raise issues of public concern. Thus, reality has entered into the legal realm.

The issue of amicus curiae intervention in international investment disputes offers a good illustration of how this change came about.

In the last few years, a number of non-governmental organizations (NGOs) have successfully drawn upon the public character of trade and foreign investment disputes to gain access to the proceedings as amici curiae (meaning “friends of the court”). They have raised a variety of arguments, ranging from jurisdictional issues to environmental and human rights considerations. This article analyzes how the practice of amicus intervention spread from interstate adjudicatory bodies to investor-state arbitrations, focusing on the recent developments under the International Center for the Settlement of Investment Disputes (ICSID).