The terrorist attacks at the start of the new millennium shook the world. In Western countries, the new threat of 'home-grown' Islamic terrorism has directed the authorities' attention towards local Muslim communities. Islamic terrorism is generally seen as a sign of the lack of integration of these communities. Authorities therefore often opt for preventive policies in which the engagement with Muslim organisations and spokespersons plays a significant role. However, this engagement comes with its own problems and dilemmas. Should authorities aim for a broad representation of the community or instead go for selective engagement? Are non-violent fundamentalist organisations also to be seen as the enemy? Should authorities enter into public debate with extremist organisations? Is it wise to link anti-radicalisation policies to more general integration policies?

Engaging with Violent Islamic Extremism shows how authorities in London, Berlin, Amsterdam, Paris and Antwerp have each developed distinctive policies, and how they have dealt with the accompanying dilemmas. It distils various approaches that can be assessed by their merits and defects, thus stimulating important reflection on the 'what', 'why' and 'how' of anti-radicalisation policy.

Dr Floris Vermeulen is assistant professor at the department of political science at the University of Amsterdam and co-director of the Institute for Migration and Ethnic Studies (IMES).

Professor Frank Bovenkerk was the first occupant of the FORUM Frank J. Buijs chair for radicalisation studies at the University of Amsterdam, from 2009 until 2012.