At the present time, various forms of violent extremism in the left- and right-wing, as well as in the jihadist milieus, seem to increase all over the world. This development produces a lot of concerns within Western societies and is often fuelled by populist actors in terms of their own purposes. The present book seeks to clarify the real situations and possible threats that are currently occurring with regard to the three considered violent extremist movements in Belgium, Canada, Denmark, France, Germany, Great Britain, The Netherlands, and the United States of America (USA).