The EU as a non-disputing party in international investment arbitration

In recent years, there has been a notable surge in amicus curiae participation in investment arbitration. In light of the EU exclusive authority over common commercial policy, the European Commission has increasingly sought to engage as a “friend of the Court”, addressing the intersection between EU law and international investment law. This article critically examines the European Commission’s role as a non-disputing party in investor-State arbitration. After exploring the EU position on investment law and the function of amici curiae in Investor-State Dispute Settlement (Sections 2 and 3), the paper scrutinizes the European Commission briefs in terms of its role as the guardian of the EU legal order (Section 4), as well as the Commission’s role in facilitating dialogue between EU law and international investment law (Section 5). Lastly, the article considers the Commission’s current and potential contribution to advancing key EU external policy values, such as sustainable development and human rights.