The new OSCE Guidebook on “The Role of Civil Society in Preventing and Countering Violent Extremism and Radicalization that Lead to Terrorism: A focus on South-Eastern Europe” is the first in a series of resources produced by the Transnational Threat Department/ Action against Terrorism Unit. This volume provides practical guidance and helpful background for both policy makers and practitioners who are working to advance civil-society-led P/CVERLT initiatives in the South-Eastern European region.