Conflict resolution between EU law and bilateral investment treaties of the EU Member States in the aftermath of Achmea

Abstract

This article examines how conflicts between European Union (EU) law and Bilateral Investment Treaties (BITs) between EU Member States (intra-EU BITs) are to be tacked following the judgment of the Court of Justice of the EU (CJEU) in Achmea (C-284/16). Starting from an analysis of the CJEU's ruling and its aftermath (Sections II and III respectively), the article argues that conflicts in the interrelation of EU law with inter se agreements, such as intra-EU BITs, are to be approached as normative conflicts between different sub-systems within the broader system of public international law and resolved in favour of EU law. This argument is based on a two-fold premise, analysed in Section IV: first, that EU law does not constitute a 'new legal order', outside of and cut off from international law, but rather a 'self-contained regime', operating 'within' the broader system of international law. Since EU law is treaty law, conflicts in its relationship with (other) inter se agreements are, therefore, to be addressed using the conflict rules of international law. Against this background, the second premise of the article is that the EU Member States have agreed on a special conflict rule to regulate conflicts between EU law and inter se agreements. That rule is the principle of primacy of EU law. Having established the applicable conflict rule, Section V expands on the consequences of its application to the conflict between EU law and investor-state arbitration clauses in intra-EU BITs affirmed by the CJEU in Achmea.