Islamic terrorism is arguably the biggest threat that western democracies are now facing. Using Membership Categorisation Analysis as a research methodology and transcripts of the recordings of the negotiations between law enforcement agencies and Mohammed Merah, a self-professed Islamic terrorist, the purpose of this paper is to analyse how an Islamic terrorist accounts for committing terrorist attacks. Taking an ethnomethodological stance, the analyses are rooted in Merah’s own practical reasoning, made visible through his identity work and the way in which he accounts for his actions and renders them intelligible as an act of Islamic terror. Findings indicate that Merah’s identity work points to a dichotomous (us and them) version of a religious and political world order in which an imagined de-territorialised Muslim community (the ummah) is being defended against the aggression of western democracies. Defence of this imagined community justifies global terrorist attacks against the enemies of Islam.