EU Enlargement to the Central and Eastern European candidate countries is widely understood as having been an important mechanism for Europeanization. The conditionality for EU membership is seen as providing incentives and sanctions for compliance or non-compliance with EU norms and rules, such as the 'Copenhagen Criteria' and the transposition of the acquis communautaire into domestic law. Critically engaging with the concepts of 'Europeanization' and conditionality within which enlargement is generally addressed, this book takes a broader comparative approach. It is the first systematic theoretical and empirical analysis of the key linkages between the simultaneous processes of enlargement, Europeanization and post-communist transition. Drawing from an unprecedented number of interviews with elites in the Central and Eastern European Candidate Countries (CEECs) and officials in Brussels, together with a thorough examination of the official documentation, the authors identify and assess the dynamic interactions between the Commission and the CEECs over regional policy - one of the most important policy areas for enlargement and the future of the EU. The nebulous nature of enlargement conditionality, how the Commission shifted the parameters over time, and the many paradoxes and weaknesses in its use made conditionality more of a myth than a coherent instrument for Europeanization.