This paper seeks to provide a preliminary framing of the issue of European Union enlargement, rendered highly urgent, after a period of relative disengagement, by Russia’s full-scale invasion of Ukraine, through a review of the principal academic and political debates surrounding the matter.

While EU enlargement may be examined from a range of perspectives, including the functioning of the Single Market or the administrative and institutional preparedness of candidate countries, the central question addressed here concerns the political and democratic integration of candidate states, as well as the European socialisation of their public spheres.

The proposal, increasingly advanced in policy discussions, of a staged or intermediate model of accession to the European Union aims precisely to highlight that economic integration, through participation in the Single Market and access to EU funds, although essential (and strongly sought by candidate countries themselves), is not in itself sufficient to ensure full political integration, adherence to the Union’s fundamental values, or the development of a broadly shared sense of European citizenship within new Member States.