This paper is the first in a series of papers that aim to address Islamist violent radicalization from different angles: the nature of violent radicalization in the context of Spain; a comparison between European, North American, and Indian violent radicalization; the need to refine territorial radicalization indexes within the context of preventing violent radicalization and the relation between Islamist violent radicalization; and other forms of violent radicalization in Europe. This series of articles builds upon the general theoretical framework established by the author in two previous works. These works are framed under the known conception of three layers of micro, meso, and macro factors contributing to violent radicalization processes. The paper starts by defining Islamist violent radicalization. Then, it explores different theoretical explanations, and finally, it proposes an explanatory hypothesis that is tested against, on the one hand, data proceeding from different institutional sources in Spain and, on the other, some initial conversations to Spanish security officials and people who were radicalized in the past and regretted it or lived very close to others that did it. In further articles, these preliminary conversations will become life stories and in-depth interviews. [ABSTRACT FROM AUTHOR]