ABSTRACT
Sometimes supranationality is a matter of a more constraining and binding way of functioning than traditional intergovernmental organizations. The European Coal and Steel Community already achieved a high level of institutional supranationality. Complexity and, in particular, regime complexity, can lead to fragmentation and particularly to legal fragmentation. Since 2010, the European Union (EU) has been facing several crises, each one questioning the future of its supranationality. For example, the reform of eurozone governance after 2010 is a relevant test for supranational governance and for the tension between efficiency and legitimacy: supranationality as an organising principle for the monetary order means a regime founded on collective adherence to the decisions of an autonomous international organisation. Claims to sovereignty are increasing not only in the new but also in old EU Member States. The chapter also presents an overview of the key concepts discussed in this book.
