The terrorist attacks of September 11, 2001 fundamentally altered the United States and the world. In response, the US adopted an aggressive policy of prevention aimed at incapacitating any potential threats, but this led the government to sacrifice civil liberties by targeting and detaining people based on speculation rather than evidence of wrongdoing. The Bush administration justified many of its counterterrorism policies, including the war in Iraq and domestic surveillance programs, on preventive grounds despite risks to core legal and ethical principles when using such a speculative predictive approach.