"This project analyses the conditions under which terrorist groups fall into decline. This is done through a systematic comparison of different paths of disengagement and exit from terrorism that have concerned different types of (a) Left-wing (b) Nationalist-Separatist, (c) Religious-Fundamentalist and (d) Right -wing terrorist groups in two European democracies (Italy and Spain) in the last 40 years (1970-2010). Many scholars have noted the cyclical nature of terrorist movements. However, scarce attention has been paid so far, within academia and outside it, to the ways in which such groups come to an end or move away from violence. Referring to social movement studies, and adopting a ‘dynamic approach’ to the study of disengagement, my research project seeks to answer these questions. It discusses the possible paths for leaving underground organisations, specifically interrelating the micro-meso-macro analytical level of analysis, exploring how the complex interactions between the social, political, and cultural environment, combined with the internal dynamics of the groups, affect the exiting from terrorism. This will be done by adopting a methodological triangulation strategy which combines a ‘large N’ quantitative study with a ‘small N’ comparative case study of different types of ‘disengaged’ terrorist groups, and several qualitative-quantitative data-collection techniques: compilation and analysis of a selective data base of underground organisations; discourse analysis of interview data; content analysis of historical records (newspapers, government documents, autobiographies, documents from organisations); and systematic consultation of secondary sources. Focusing on different contexts and different kinds of movements (Right-wing, Left-wing, Ethno-nationalist and Religious-fundamentalist), I apply a “most-different” design to paired comparison in order to look not (only) for correlations between variables but rather for similar mechanisms."