This book analyses the impact of the European Union (EU) integration process on decision-making structures in a new EU Member State. It provides a systematic, quantitative network analysis of the effects of Europeanization on the institutions, policy processes, power constellation and conflict among national elites. Providing a detailed case study on Romania in comparative perspective, the author focuses on six policy networks to provide a cross-sector and cross-time comparative analysis. It explores mandatory EU pressure in the area of immigration and asylum and the implementation of various EU directives during the negotiation period and continued and post- integration. It also examines soft non-mandatory Europeanization in the social sector and provides a third control case on domestic reform, fiscal decentralization in the education sector, where the EU influence is absent. Measuring the impact of Europeanization both before and post integration, this book has considerable implications for the study of current and future candidate states. It will be of interest to students and scholars of EU enlargement, Europeanization studies, European politics, especially Central and Eastern European politics.