Between a Rock and a Hard Place: The Court of Justice’s Judgment in Case Slovenia v. Croatia

The Slovenia v. Croatia case (Court of Justice, judgment of 31 January 2020, case C-457/18) is a complex and politically charged one. Here, the Court of Justice was indirectly called upon to pronounce on the legal effects of an international arbitral award delimiting the territorial and maritime boundary between two Member States – the validity of which remains fiercely contested by one of the parties. This Insight analyses the Court of Justice’s reasoning in the case at hand and argues that, although the Court was arguably caught between a rock and a hard place, its misconstruction of the subject matter of the action and its failure to engage with the res judicata effects of the arbitral award within the EU legal order weaken the persuasive force of its line of argumentation.