This perceptive analysis examines the effect of the EU on Turkish counter-terrorism polices towards the Kurdistan Workers Party (PKK) and the Islamic State (ISIL), and aims to investigate the extent to which the EU has developed the capacity to play a role in Turkish counter-terrorism policy through promoting democratisation. The book analyses the EU’s normative role in Turkey during four distinct periods: the inertia (1984-1999), the conditional transformation (1999-2004), the social transformation (2004-2015), and the backsliding periods (2015-2020). Ethem Ilbiz and Christian Kaunert consider how the paradigm shifts in Turkish counter-terrorism policies that occurred during these periods have their basis in different domestic and EU-level factors. Exploring the EU’s relations with candidate countries, the book highlights how its influence on Turkey is connected to the viable prospect of Turkey’s membership. Examining one of the most important policy areas of European integration, this book will be critical reading for academics and students of European politics and policy, international relations, terrorism and security, and regional studies. It will also be beneficial for practitioners, politicians, and non-governmental and civil society organizations.