The European Union has not admitted a new member state since Croatia in 2013, while the United Kingdom left the block in 2020. Enlargement, however, is now back on the EU agenda. Western Balkan countries such as Montenegro are coming close to EU membership, and the new geopolitical context has fostered a reconsideration of the EU enlargement approach altogether. What factors will determine which new countries will join the European Union and when, and what are the next steps?