TY - JOUR N2 - This article examines the consequences of the Court of Justice of the European Union’s (CJEU) ruling in Achmea concerning Investor-State Arbitration (ISA) under intra- EU Bilateral Investment Treaties (BITs) from a treaty law perspective. It begins by briefly setting out the arguments of Advocate General Wathelet and the CJEU supporting their different positions on whether intra-EU BITs ISA clauses are compatible with EU law. The article then proceeds to analyse Achmea’s implications for intra-EU BIT ISA. It concludes that, as a result of the CJEU’s ruling, arbitral tribunals are deprived of their jurisdiction to entertain investors’ claims brought under intra-EU BIT ISA clauses. Finally, the article argues that Achmea’s applicability to cases brought under intra-EU BIT ISA clauses is limited, using the application of EU law as a relevant qualification. In order for an arbitral tribunal to be deprived of its jurisdictional competence as a result of Achmea, it must be entitled to interpret and apply EU law directly or indirectly in determining its jurisdiction. L1 - http://journals.pan.pl/Content/117543/PDF/10_Georgaki.pdf L2 - http://journals.pan.pl/Content/117543 PY - 2019 EP - 226 DO - 10.24425/pyil.2020.134482 KW - Achmea KW - arbitral tribunal KW - intra-EU BITs KW - Investor State Arbitration KW - jurisdiction A1 - Georgaki, Konstantina A1 - Papanastasiou, Thomas-Nektarios PB - Institute of Law Studies PAS PB - Committee on Legal Sciences PAS VL - No XXXIX DA - 2021.01.27 T1 - The Impact of Achmea on Investor-State Arbitration under Intra-EU BITs: A Treaty Law Perspective SP - 209 UR - http://journals.pan.pl/dlibra/publication/edition/117543 T2 - Polish Yearbook of International Law ER -