Al Qaeda and its affiliated groups offer the analyst a highly complex challenge. The current literature classifies Islamic terrorist organizations as either networked or hierarchical. Yet, this classification fails to account for the appearance on the international stage of a new type of global terrorism. Most notably, it does not capture the structure and mode of operation of Al Qaeda as it emerged after the 2001 U.S.-led assault on Afghanistan. This article therefore introduces a new concept - the Dune organization - that is distinct from other organizational modes of thinking. This conceptualization leads to a new typology of Islamic terrorist organizations. This typology concentrates on organizational behavior patterns and provides a framework for a comparative analysis of terrorist movements, which is applied to a study of Al Qaeda, Hizballah, Hamas, and the Palestinian Islamic Jihad.