Summary
De-radicalisation is the attempt to help people leave extremist movements and the outlook that goes with them. As a field of state programmes and research it belongs to counter-terrorism; in Western Europe such programmes multiplied after 11 September 2001. The term is still defined inconsistently. Its most useful distinction is between de-radicalisation, a change in what someone believes, and disengagement, a change in what they do: people can stop taking part in violence without giving up the ideology.
Researchers in the field also stress that leaving tends to hinge on a relationship, with a mentor or friend who supports the change, more than on winning an argument.
Rationale
We use this field with a caveat. That people leave violence without first changing beliefs fits our doubt about any “switch inside of us”. Its premise, that authorities decide whose outlook needs correcting, doesn’t.