Against a backcloth of tumultuous events in Europe, the EU faces once again the fateful question of moving towards federal union or let flexible integration guide the Union. The sixth volume in Interdisciplinary European Studies explores the coexistence of deepening political integration and flexible patterns of integration in the EU. The book brings together scholars from economics, law, and political science to provide insights into issues with a bearing on the future of the EU: the crisis of rule of law and political values, the move towards a European defence union, the power of the new European public prosecutor’s office, the prospects of financial stability through the Recovery and Resilience facility, and the state of European parliamentary democracy. The chapters are based on up-to-date research findings and succinct assessments of the current state of affairs and ongoing debates. They conclude with policy recommendations for decision-makers on European and national levels.