The direct effect (or lack thereof) of international law in the EU legal order, today

The relationship between international law and European Union (EU) law remains the subject of intense debate. This Chapter revisits a crucial aspect of that broader conversation: the direct effect – or absence thereof – of international law within the EU legal order. From a primarily doctrinal standpoint, we examine the trajectories of this ‘external’ form of direct effect in the case law of the Court of Justice of the EU (CJEU) with two objectives in mind. First, to critically assess both the virtues and the (many) flaws of this jurisprudence, while advancing alternative approaches to the conceptualization and application of direct effect in this area of EU law. Second, to compare the role of direct effect in shaping the legal effects of international law in the EU legal order with the case law on the direct effect of EU law in the legal orders of the Member States. Placing these two phenotypes of direct effect side by side allows us to reflect more widely on the contemporary content, scope, and limits of the principle. In this vein, the Chapter aspires to provide an original contribution to the understanding of direct effect as a primus inter pares principle and as a constitutional cornerstone of the EU legal order. We argue that the recurrent non-recognition of direct effect to international agreements often rests on considerations largely external to law, revealing direct effect as a political construct, not only as a legal notion. This tendency is reinforced by the increasingly common practice of expressly precluding external direct effect in the very text of international agreements concluded by the EU – a development with far-reaching consequences for the role of the CJEU as the principal ‘gatekeeper’ of EU law vis-�a-vis international law. Ultimately, we contend that the denial of external direct effect – amounting to the denial of legality review of EU law – must be handled with utmost care, not least because the CJEU often deploys it to pursue objectives which, though politically legitimate, have little to do with the enforcement of EU law.