Civil liberties and terrorist detainees

Following the events of September 11, Bush issued an executive order authorizing the NSA to monitor communications between suspected terrorists outside the U.S. and parties within the U.S. without obtaining a warrant pursuant to the Foreign Intelligence Surveillance Act, maintaining that the warrant requirements of FISA were implicitly superseded by the subsequent passage of the Authorization for Use of Military Force. The program proved to be controversial, as critics of the administration, as well as organizations such as the American Bar Association, claimed it was illegal. In August 2006, a U.S. district court judge ruled that the Terrorist Surveillance Program was unconstitutional, but the decision was later reversed. On January 17, 2007, Attorney General Alberto Gonzales informed U.S. Senate leaders that the program would not be reauthorized by the president, but would be subjected to judicial oversight.

On October 17, 2006 Bush signed into law the Military Commissions Act of 2006, a bill passed in the wake of the Supreme Court's decision on Hamdan v. Rumsfeld, which allows the U.S. government the ability to prosecute unlawful enemy combatants by military commission rather than the standard trial. The bill also denies them access to habeas corpus and, while barring torture of detainees, allows the president to determine what constitutes torture.

On March 8, 2008, Bush vetoed H.R. 2082, a bill that would have expanded Congressional oversight over the intelligence community and banned the use of waterboarding as well as other forms of enhanced interrogation techniques, saying that "the bill Congress sent me would take away one of the most valuable tools in the war on terror."

The CIA once considered certain enhanced interrogation techniques, such as waterboarding, legally permissible.President Bush has consistently stated that the United States does not torture. Bush can authorize the CIA to use the simulated-drowning method under extraordinary circumstances The CIA has exercised the technique on certain key terrorist suspects and were given permission to do so from a memo from the Attorney General. While the Army Field Manual argues "that harsh interrogation tactics elicit unreliable information", the Bush administration states that these enhanced interrogations have "provided critical information" to preserve American lives.