In April 2019, the Court of Justice of the EU (‘CJEU’) handed down its Opinion (C-1/17) on the compatibility of the Investment Court System (‘ICS’), that is the Investor-State Dispute Settlement (‘ISDS’) mechanism under the EU-Canada Comprehensive and Economic Trade Agreement (‘CETA’), with EU law. This article puts Opinion 1/17 in its broader (policy and legal) context, focusing on the salient issue of compatibility with the principle of autonomy of the EU legal order. It argues that the Court's openness to this judicial competitor was an acknowledgment of the need to maintain the powers of the Union in international relations. However, Opinion 1/17 should not be perceived as an automatic green light for any future investment court (such as the Multilateral Investment Court) as the autonomy test it introduces is a rather difficult one to pass.
