In the years following 9/11, threat assessments necessarily focused on the dangers posed by al-Qaida, its affiliates, and those inspired by its ideology. There are signs, however, that the threat today is more complex and diffuse, comprising extremists from all parts of the ideological spectrum who may act in small “self-starter” groups or, in some cases, as “lone wolves.” The paths to extremism are more varied than ever before, and as our understanding of contemporary patterns of radicalization has advanced, terrorism prevention initiatives have become more prevalent in the counterterrorism repertoire at the national and multilateral levels.
As many states have elaborated terrorism prevention strategies in recent years, they have begun to confront similar challenges. Among these is the challenge of program evaluation. Is the turn toward prevention an effective response to the diverse extremist threats that states face today? How can the effectiveness of prevention policies be measured? What approaches have states advanced in evaluating the impact of terrorism prevention initiatives? In responding to this challenge, can lessons be gleaned from efforts to evaluate programs in related policy domains? This policy report provides an initial discussion of these questions. It draws on the discussions during a meeting entitled “Colloquium on Measuring Effectiveness in Counterterrorism Programming” and held in Ottawa on 9–10 February 2012, as well as discussions with experts, government officials, and an initial desktop literature review.