This rise of radical Islam can be attributed to a multitude of factors. Among them are the search for identity and recognition, the feeling or experience of marginalization � both politically and economically, opposition to secular nationalist ideologies, frustration with regimes that are perceived as apostate and corrupt, the weakness of educational systems, only to name a few. Several war-torn countries, where the state has lost control of part of the territory, have served as virtual breeding grounds for terrorists, such as Afghanistan, Somalia, and more recently Iraq and Syria. Terrorist groups have also improved their mechanisms of propaganda and recruitment. With the recent Arab revolutions, many observers had hoped that Al Qaeda and its affiliates would lose ground. This was mainly based on the assumption that many followers would be diverted from the path of radicalism and violence through the observation that change could be achieved by peaceful means. However, things developed quite to the contrary. Radical Islam has profited from a dramatic increase in popularity the last few years, and Al Qaeda and its affiliates like Jabhat al-Nusra as well as its split-offs, namely ISIS, have witnessed what Mohammad Abu Rumman ably describes as �Al Qaeda Spring�, having undergone a period of adaptation. The terrorist network has moved from a phase of a single Al Qaeda into one of multiple Al Qaedas operating independently on numerous fronts. With this volume, we are publishing several of the papers, which were presented at our 2014 conference on �The Rise of Religious Radicalism in the Arab World�. The papers present different perspectives on radicalization in the aftermath of the recent Arab revolutions and crises.