The use of violence by dissidents in contemporaneous democratic states poses a significant threats to the integrity, values and prosperity of the society as a whole. This dissertation argues that when such threats are not deterred by traditional law enforcement, they need to be countered by extraordinary means. This repression should take the form of psychological terror. The argument is that psychological terror can shape the behaviour of dissidents and force them away from violence towards conventional politics. The validity of the argument is demonstrated by three historical cases where traditional law enforcement was bypassed and some forms of psychology were used for repression. The first case involves the U.S. government facing the troubles of the late 1960s. The second case happens in the USSR and portrays a regime pro-actively countering dissidence through preventive warnings. The last case illustrates the East German government using attrition methods in order to neutralize critics of the regime. The characteristics of the three cases are collected in an effort to design a new enforcement terror. The main similarities between all cases are the pro-active way dissidence was countered, the use of covertness instead of overt and traditional law enforcement, and the use of psychology to repress. Based on this, a repression process in three stages is designed, composed of pre-enforcement, enforcement and postenforcement. Pre-enforcement encompasses the detection of dissidents, their surveillance and subsequent targeting for enforcement. During the enforcement stage the terror is applied and the dissident is neutralized. The post-enforcement stage includes everything that comes afterwards, such as the disengagement of the dissident and his eventual reorientation. The dissertation concludes with a brief reality check of how enforcement terror would perform in the light of the surveillance capabilities that today's information technologies provide. Master of Science (Strategic Studies)