The Judgment of the Court of Justice of the European Union (CJEU) in Slovenia v. Croatia marks the anticlimax of a long-running territorial dispute. It is also only the sixth time the CJEU has issued a judgment in a case instituted by one European Union member against another. Among these cases, it is the first to consider an arbitral award in a dispute between members, the first to consider a boundary dispute between members, and the first to be dismissed for lack of jurisdiction. The Court found that it cannot rule on alleged infringements of European Union law when these arise from the breach of a treaty falling outside of the Union's subject-matter competence. Most directly, the Judgment may pose significant consequences for European Union internal affairs in the near term, such as Croatia's ambitions to join the Schengen Area and the Eurozone. More broadly, several of the Court's findings will be relevant beyond the European legal order, particular those concerning the meaning and effect of “ancillary” legal questions, and the bilateral or multilateral character of a dispute involving admission to an international organization.

This article focuses on state recognition in the European context and on the admission of states to the Council of Europe after the end of the Cold War. It argues that two global trends identified by John Dugard in the 1980s have continued since then: a common approach to state recognition has been adopted and the criteria for state recognition have increasingly been given normative content. This reflects that the constitutive theory of state recognition continued to be popular. The two trends have not automatically resulted in a more legal approach to the issues, as the case study of Bosnia and Herzegovina illustrates.