Results from a topically designed simulation of international CT support the four main hypotheses under examination: (1) international CT is impossible without interorganizational coordination; (2) political partnerships are neither sufficient nor necessary to the formation of interorganizational coordination; (3) internal organizational orientations threaten effective coordination; and (4) competing organizational objectives hamper effective coordination. The author argues that international CT is impossible without interorganizational coordination between public agencies at home and public agencies abroad. This type of interorganizational coordination of public agencies, although necessary to mount an effective counterterrorism campaign, is rare. Instead, substituting for interorganizational cooperation are political partnerships, which the author argues, are neither necessary nor sufficient for international interorganizational cooperation. Since interorganizational cooperation does not emerge spontaneously, it is up to managers to deliberately pursue an organizational culture that is oriented to cooperative institutional objectives that would preferably be accountable to international institutions. The topically designed simulation modeled seven days of interaction between various organizations on an island in Southeast Asia. The simulation highlighted the importance of effective interorganizational coordination to reaching international CT objectives. Future research should examine the importance of interorganizational coordination to domestic CT. Notes