Social scientists have speculated about the most effective ways for governments to react to the terrorist attacks on the World Trade Center on 11 September 2001. Many of these speculations have addressed the danger of responding in a manner that would increase the likelihood of future attacks against America and its allies. Drawing upon data from interviews with people centrally involved in the intergroup conflict in Northern Ireland, we provide analyses of how intergroup dynamics affect individual support for violence and also suggest that violent military intervention is not likely to reduce future terrorist attacks. To the contrary, such intervention will likely fuel violent intergroup conflict and bolster the membership of terrorist groups. This research note is based on analyses of an ongoing study involving a series of detailed semi-structured interviews with representatives from all aspects of the ethnic and political spectrum of Northern Ireland. Our participants include members of paramilitary groups, civil rights demonstrators, the security forces, politicians, community workers, church leaders and victims of violence.