At the time of the publication of this volume the European Union is facing its biggest crisis. The most apparent dimension of the current challenge is economic, manifested most spectacularly by the crisis of Greece and of the eurozone. But the way to the current situation was paved with eminently political decisions. When the leaders of the EU have decided to re-interpret the original convergence criteria, when they failed to initiate excessive deficit procedures against big member states, or when they procrastinated over the responses to the financial crisis they behaved according to the a political logic. The present volume, while not directly focusing on the crisis, helps to understand this logic of decision-making. Due to the permanent changes the European Union remains an UPO Unidentified Political Object -, as the legendary Commission president, Jacques Delors, put it, but the analyses of theoretical issues, of specific policy areas and of the central political processes bring the readers closer to a realistic and systematic knowledge of the subject.