The terrorist attacks of September 11, 2001, exposed every person in the USA to an experience that, in recent decades, was unprecedented in its scope and traumatic impact. Perhaps over 100,000 individuals directly witnessed these events, and many others viewed the attacks and their aftermath via the media (Yehuda, 2002). It has been argued that this national trauma “influenced and will continue to influence the clinical presentation of patients seeking health care services” in the USA (Yehuda, 2002, p. 108).

A wide range of responses can be expected following traumatic life events. Research conducted after the Oklahoma City, OK, bombing indicates that responses to a terrorist attack are likely to be highly variable (North et al., 1999). Research in the broader field of stress and coping has also demonstrated considerable variability in emotional and cognitive responses to stressful experiences (Silver & Wortman, 1980;Wortman & Silver, 1989, 2001). Despite advances in understanding reactions to traumatic events, our understanding of responses to community-level events in general, and terror attacks in particular, is limited. Progress in understanding the social and psychological process following such occurrences requires examination of how responses to a variety of stressful events are similar and different at both the group and individual level. Research has matured to the point that large-scale, prospective, longitudinal studies with the scope to examine mediators and moderators of adjustment processes are not only possible, but also necessary (North & Pfefferbaum, 2002). Moreover, the threat of future terrorist attacks demands that a higher level of urgency and research sophistication be directed not only at understanding the effects of such attacks, but also at the individual and social variables that predict psychological outcomes to such events over time.