The study of sources from inside the armed opposition in Iraq provides a detailed picture of the military and ideological realities on the ground. On the basis of the various publications of the Sunni rebel groups, we can identify the protagonists of the Jihadi movement in Iraq and trace the evolution of Jihadism since the beginning of the war. This inside view also allows us to understand the conflict dynamics driving the different militia forces and contributing, therefore, to the extension of violence between religious groups. The analysis of the ideological arguments used by the main groups involved shows that armed struggle essentially feeds upon the notion of “jihad”, which appears to be the main source of legitimization of blind violence at present. To the Jihadi movement, the Iraq war represents an ideological and historic turning point.