September 11 Attacks

United States domestic policy was also transformed in the aftermath of the September 11 attacks. Local governments around the country looked to improve their preparations for a terrorist attack. Of particular concern was the prospect of an attack involving chemical or biological weapons. Several letters containing potent anthrax spores were posted to the offices of prominent media figures and politicians in October 2001, and five people died after being exposed to the spores. The rash of anthrax cases sparked fears that terrorists were carrying out a biological attack. No link between terrorists and the anthrax letters was found, but the fear prompted renewed efforts by public health organizations to prepare for such an eventuality.

For some in the US government, the lesson of the September 11 attacks was that authorities needed greater abilities to identify potential terrorists within American society and take whatever actions were necessary to stop them from carrying out attacks. In October 2001 the US Congress passed a bill that expanded police powers, allowing for more wire-tapping of conversations and for the surveillance of computers and e-mail.

United States officials were especially alarmed that the September 11 terrorists had been able to live, work, and freely move around the United States without anyone realizing what their plans were. The new anti-terrorism law included a provision that would allow immigrants suspected of terrorist activities to be detained for seven days without charges and in some cases held for an additional six months. It would also be harder for foreign visitors to obtain US visas, and US authorities would have greater latitude to bar entry to people suspected of having links to terrorist organizations. Some of these laws were echoed by legislation passed by other Western governments, including changes to anti-terrorist laws in the United Kingdom.

As the US government worked to strengthen its defences against terrorism, it also looked back at its failure to prevent the September 11 attacks. Two investigations of the circumstances surrounding the attacks began in 2002. The first, a joint inquiry of the intelligence committees of the US Senate and House of Representatives, examined the activities of the FBI, CIA, and other intelligence agencies prior to and following the attacks. Its report, publicly released in 2003, detailed systemic problems among these agencies, including poor organization, inadequate staffing and training, and, above all, a failure to share crucial information with one another that might have led to detection of the September 11 plot. It was hoped that some of these issues would be resolved by the creation of the Department of Homeland Security, which would coordinate the work of several federal agencies.

The second and larger investigation, by an independent commission, released its findings in 2004. During its 20-month investigation, the commission interviewed more than 1,000 witnesses, including President Bush, and reviewed more than 2 million documents. The report of the 9/11 Commission found that there had been a failure of 'policy, management, capability and, above all, imagination' in handling the threat from Al-Qaeda. It criticized the Clinton and Bush administrations for failing to combat the terrorist threat and recommended the creation of a national counter-terrorism centre to unify intelligence and operational planning of the 15 different intelligence agencies in the United States against Islamist terrorists.

In May 2006 the only man to be prosecuted in relation to the attacks, a French citizen originally from Morocco named Zacarias Moussaoui, was sentenced to life imprisonment for conspiring to fly an aeroplane into a public building. He had confessed to his plans after he was arrested on an immigration charge prior to September 11, although it is unlikely that he knew about the plans for that day.