Extremism: Laurie Taylor talks to Julia Ebner, Senior Research Fellow at the Institute for Strategic Dialogue, about her experience of going undercover amongst political extremists, including neo Nazis, Islamic jihadists and anti feminists. Also, Daniel Koehler, founding Director of the German Institute on Radicalization and De-Radicalization Studies (GIRDS) discusses the side-switchers and defectors who migrate across extremist groups and ideologies. Ray Hill is a positive example of a former British fascist, turned informant on the far right. Unlike Sascha Lemanski, a German far right activist who crossed over into Islamic jihadism. Can an understanding of the phenomenon of side-switching help us understand the way in which people become radicalised and help combat terrorist violence?

Producer: Jayne Egerton