This paper argues that international security studies can most profitably engage the issue of international terrorism by considering terrorist groups as transnational social movement organizations. It takes as its case Al Qaeda's role in Southeast Asia, focusing especially on the efforts of Al Qaeda leaders to align the demands and grievances of local Islamist movements and to spread a set of tactics and methods of political violence. In so doing, the paper builds on the often-neglected literature on the politics of terrorism while tying the argument to prevailing debates over social movements. The paper thus aims at clarifying the ways in which Southeast Asian organizations have adopted Al Qaeda's tactics and language but appear to be addressing primarily local or provincial concerns. This perspective also draws terrorism into current discussions of international security while maintaining a detailed focus on the interactions of individual agents and larger violent movements.