Since the 1990s, there has been a growing concern about the resurgence of extremist and radical movements in the Western world. Although a variety of challenges to the liberal democratic order have emerged, the main focus of concern among academics, policy-makers and practitioners within Europe and beyond has been on the growth and activities of Islamists and to a lesser extent the extreme right. However, these forms of extremism are seldom placed alongside each other, and in a manner that is sensitive to both the causes and consequences of extremist mobilization. This book presents new...