The ad hoc briefing paper Preventing violent radicalisation and terrorist recruitment in the EU - The threat to Europe by radical Islamic terrorist groups provides an original analysis and evaluation of the different strategies that are meant to deal with such phenomena, as well as their effectiveness. This perspective takes into account the dynamics of actions/reactions between the various parts involved in violence and its repression, thus going beyond recommendations mainly aiming at controlling the networks through which individuals enter the radicalizing dynamics, in a worst-case scenario perspective. The core point of the paper is to transgress the different forms of self-censorship that exist in the field of the counterterrorist public policies, by insisting upon the fact that some of the measures taken can contribute to the radicalisation, or more accurately, to the dynamics of escalation. The priority is then to move the focus, while widening the angle of the problem, to highlight the interactions not only between clandestine organisations and reference fields but also public authorities, journalists and others. The question of the radicalisation must be reconsidered and redefined as a subsidiary of the questions on escalation and de-escalation dynamics of the conflicts. The ad hoc briefing paper is thus structured as follows: the first part aims at understanding the radicalisation processes; the second part deals with the questions of clandestineness, radicalisation and recruitment; the third part deals with the dilemma faced by authorities and their policies, that can either lead to an escalation or a de-escalation, depending on whether they tend to mimetic rivalry or distanciation. Finally, the paper provides certain policy recommendations, mainly based on favouring distanciation, taking into account the pernicious effects of intensified measures of control, repression or war on violent radicalisation, and controlling and supervising counter radicalisation.