Leaders figure significantly in radicalization processes that can ultimately lead to terrorism. This article attempts to explain radicalization as a process of interaction between leaders and their followers. We argue that the process of radicalization includes five stages: pre-radicalization, self-identification, indoctrination, commitment, and jihad ideologization. In the case of the Bali bombers, the process was strengthened by external environmental conditions that enabled leaders to gain broad support from the community. In our analysis we rely on a combination of interviews with convicted terrorists and previously unexamined documentary evidence.