The authors draw on data from a national random digit dial (RDD) telephone sample of 1,549 adult Americans conducted between October 15, 2001, and March 2, 2002, to explore the impact of a need for security on support for national security policies in the aftermath of the 9/11 terrorist attacks. They examine support for protective government policies among individuals who vary in their ability to feel secure in the aftermath of terrorism, exploring the interaction between perceived threat and felt security. Most Americans reported a sense of security after the 9/11 attacks. But a sense of insecurity among a minority of Americans coupled with a perceived threat of future terrorism increased support for both domestic and international security policy—the curtailment of domestic civil liberties, tougher visa checks, and support for the war in Afghanistan. The authors' findings underscore the diverse ways in which individuals react politically to a common external threat.