One of the biggest challenges to conducting research on radicalization to violent extremism is how to further knowledge in the absence of easy access to radical individuals. This lack of access makes it particularly difficult to fulfill the demand for original data on radicalization to violent extremism and on strategies to counter it.

This chapter presents the Royal United Services Institute’s (RUSI) effort to overcome this challenge. RUSI’s milieu approach takes into consideration the importance of the context in which specific cases of radicalization take place. This is based on an understanding that research participants within these areas are able to relay contextual information about potential grievances or broader incentives impacting radicalization. The chapter highlights that these participants are frequently able to share actual knowledge of radicalization based on their lived experiences and knowledge of events affecting friends, colleagues, and family members. This approach additionally recognizes the expertise of local communities and positions authorities to learn from them.

The chapter presents the theoretical basis and the practical implications (site selection, identifying and accessing participants; selecting research methods; and analyzing data) of applying the milieu approach using case study examples of research conducted by RUSI. These include a five-country study (UK, Canada, France, Germany and the Netherlands) on gender and radicalization, research on radicalization among internally displaced persons (IDPs) and host communities in Iraq, and the radicalization of Central Asian labor migrants in Russia. The chapter highlights the challenges faced, ways of overcoming them, and key takeaways and recommendations for those interested in applying the milieu approach.