On September 11, 2001, a series of coordinated attacks were carried out at the World Trade Center in New York City and the Pentagon in Washington, DC, leaving approximately 3,000 dead in the immediate aftermath. The attacks were carried out by 19 hijackers who took control of four commercial airliners--two struck the World Trade Center, one struck the Pentagon, and a fourth crashed near Shanksville, Pennsylvania, after a struggle between the hijackers and the passengers. Al Qaeda fell under immediate suspicion in the days following the attacks. Although the organization initially denied involvement, al Qaeda founder Osama Bin Laden claimed responsibility for the attacks in 2004, citing US support of Israel, the presence of US troops in Saudi Arabia, and US foreign policy toward the Arab world as motives for the attacks.
The legal effects of the attacks have been far-reaching during the past decade. In an international military response, President George W. Bush launched the War on Terror, and the ongoing use of military force has been the source of deep controversy in the international community. The US also undertook a series of domestic legal actions intended to expand the ability of US intelligence and law enforcement authorities to prevent future attacks. The most notable of these efforts was the passage of the Patriot Act and the expansion of federal surveillance authority. These legislative and executive actions have been both touted as necessary for domestic safety and decried as resulting in severe civil rights abuses.
As a result of military actions and increased efforts to combat terrorism, the US has detained and interrogated suspected terrorists at the Guantanamo Bay military base in Cuba--sparking allegations of torture and political and legal conflicts over the status of detainees held at the facility. The potential prosecution of these detainees also created tension between civilian and military authorities, especially in regards to the creation of a new body of military commissions to handle the trials and the habeas corpus rights of the accused terrorists.