Collective versus unilateral responses to terrorism

Global terrorism presents collective action issues for targeted nations. Proactive measures (e.g., preemptive strikes) against terrorists create external benefits for all at-risk nations. In contrast, defensive actions deflect attacks to softer targets, thereby giving rise to external benefits to protected foreign residents and external costs to venues abroad. Coordinated antiterrorism measures are particularly difficult to achieve when many nations must participate and nonparticipants can undo the efforts of others. Thus, freezing terrorists’ assets or abiding by a no-negotiation pledge pose difficult collective action problems. These same concerns do not plague decisive action against domestic terrorism.