This team of international experts analyses the possibilities and limitations of preventing or reducing terrorism by addressing the factors that give rise to it and sustain it. The key questions raised include: what are the main circumstances that provide preconditions for the emergence of various types of terrorism? What are the typical precipitants that trigger terrorist campaigns? To what extent is it possible to reduce the problem of terrorism by influencing these causes and circumstances? Should we address those factors that sustain terrorist campaigns rather than root causes?