The proposed study investigates long-term ideological developments in Islamist ideology and how this influences the formation of attitudes, opinions and beliefs in the European Muslim diaspora. In particular it focuses on the question how militant ideologies transmit political violence from one social setting into another. Through a longitudinal and quasi-experimental design the project assesses the impact of three emerging political landscapes evoked by the Arab spring on the ideology of al-Qaeda (jihadism): Countries with regime change (Tunisia, Egypt), without regime change (Yemen, Saudi Arabia), and countries in a civil war (Syria). The militant ideology of the jihadi movement explains in its media to its constituency why it is necessary, beneficial and justified to engage in violent activism. The long-term development and the transnational transmission of this rationale is the focal point of the study. It investigates the ideological mechanisms in jihadi transnational media through which local and regional events in the Middle East translate into a global military doctrine. While this doctrine sets jihadism apart from political Islam (e.g. Muslim Brotherhood) it is decisive to understand whether both movements will converge or drift apart in their ideologies as they react and reposition themselves in the context of the three different political conditions evoked by the Arab revolutions. The study then moves on to investigate how emerging claims, positions, and sentiments expressed in the jihadi media resonate within Muslim communities in Germany and the UK. To this end it develops and pre-tests a survey instrument that rates the extent of rejection/endorsement of different aspects in Islamist thinking, including the legitimacy of political violence.