What kind of Europe does enlargement produce? Debating implications on territorial cohesion

This article debates the implications of enlargement of the European Union (EU) in the Western Balkans. Drawing on literature on multi-level and territorial governance, the article argues that enlargement has the potential to strengthen a territorially cohesive and democratic Europe. Simultaneously, admitting new members risks importing conflicting values that contribute to a reassertion of national executive control, resulting in a “Europe of the Nations”. The debate is illustrated through the Budapest-Belgrade railway. The railway is a cross-border infrastructure project situated at the intersection of geopolitical struggles around connectivity, Chinese influence and EU enlargement. The analysis draws on 13 expert interviews conducted with actors in Hungary and Serbia between November 2024 and February 2025. The case demonstrates how infrastructure can physically connect territories while bypassing multi-level coordination and territorial development priorities. The article concludes that enlargement is most likely to support European cohesion when accompanied by transparent governance, civil-society involvement, cross-border cooperation and shared spatial visions that strengthen territorial and democratic accountability.