Abstract Recent decisions of European and national courts, as well as those of arbitral tribunals, concerning the Achmea saga seem to be plentiful enough to draw preliminary conclusions as to the relationship between EU law, intra-EU international investment agreements (IIAs) and the national laws of EU-Member States. In order to get the proper picture of the situation, however, it is necessary not only to analyse the recent decisions of the Court of Justice of the European Union (CJEU) and their consequences from these three perspectives, but, equally, to understand how they interact with each other. Such an analysis indicates the real possibility of the emergence of a rift between the practice of the EU and national courts rejecting the validity of investment arbitration agreements, on the one hand, and investment tribunals, on the other. In any case, such a divergence would put into question the IIAs’ claim to provide a stable regulatory framework for international investments in the EU, which, in turn, would strengthen the argument for termination of intra-EU IIAs.