Abstract
May 1, 2024 marked the 20th anniversary of the EU’s eastward enlargement. At that time, ten new member states joined the European Union, seven of which belonged to the former Eastern bloc. The enlargement is a success story, as the new members have since achieved high growth rates, and this has driven the convergence process between old and new member states. In view of increasing geopolitical crises, including at the EU’s direct external borders, only a prosperous EU can remain an anchor of stability. The following questions arise: What impact has the enlargement had on the old and new EU member states? What lessons can be applied to future enlargements, for example with regard to (delayed) accessions to the internal market and the eurozone?