Are public views on anti-terrorism policies driven by concerns about future threats or by emotional responses to a prior attack? A terrorist attack on the scale of 9/11 is both a harbinger of future threat and a discrete, one-time national trauma. We sought to distinguish between a) perceptions of the future threat of terrorism and b) responses to the 9/11 attacks themselves as predictors of Americansâ national security policy preferences. Using an anonymous Web-based survey methodology, we surveyed a nationally representative sample of US adults (N=1613, 75% response rate) in late 2006 and early 2007. Respondents rated the likelihood of another terrorist attack occurring on U.S. soil in the near future. They also reported any experience of terror-related posttraumatic stress symptoms (PTS) in the form of intrusive thoughts and images resulting from 9/11. In addition, respondents expressed their degree of support for anti-terrorism policies in three ways: 1) as having desired an aggressive U.S. response to 9/11, 2) as support for ongoing military involvement in Afghanistan and Iraq, and 3) as willingness to sacrifice civil liberties for security. Multiple regression analyses adjusting for political affiliation, general psychological distress, exposure to 9/11, and other key variables revealed that both perceived likelihood of future terrorism and 9/11-related PTS independently predicted greater support for all three categories of anti-terrorism policies. Moreover, perceived likelihood and PTS interacted such that perceived likelihood of future terrorism did not predict policy preferences among individuals high in PTS. Public views on future-oriented policies may be disproportionately influenced by distressing experiences from the past. ..PAT.-Unpublished Manuscript [ABSTRACT FROM AUTHOR]