Khalid Sheikh Mohammed in the context of "Mohamed Atta"

"Enhanced interrogation techniques" or "enhanced interrogation" was a program of systematic torture of detainees by the Central Intelligence Agency (CIA), the Defense Intelligence Agency (DIA) and various components of the U.S. Armed Forces at remote sites around the world — including Abu Ghraib, Bagram, Guantanamo Bay, Rabat, Udon Thani, Vilnius, Bucharest and Stare Kiejkuty — authorized by officials of the George W. Bush administration. Methods used included beating, binding in contorted stress positions, hooding, subjection to deafening noise, sleep disruption, sleep deprivation to the point of hallucination, deprivation of food, drink, and medical care for wounds, as well as waterboarding, walling, sexual humiliation, rape, sexual assault, subjection to extreme heat or extreme cold, and confinement in small coffin-like boxes. A Guantanamo inmate's drawings of some of these tortures, to which he himself was subjected, were published in The New York Times. Some of these techniques fall under the category known as "white room torture". Several detainees endured medically unnecessary "rectal rehydration", "rectal fluid resuscitation", and "rectal feeding". In addition to brutalizing detainees, there were threats to their families such as threats to harm children, and threats to sexually abuse or to cut the throat of detainees' mothers.

The number of detainees subjected to these methods has never been authoritatively established, nor how many died as a result of the interrogation regime, though this number could be as high as 100. The CIA admits to waterboarding three people implicated in the September 11 attacks: Abu Zubaydah, Khalid Sheikh Mohammed, and Mohammed al-Qahtani. A Senate Intelligence Committee found photos of a waterboard surrounded by buckets of water at the Salt Pit prison, where the CIA had claimed that waterboarding was never used. Former guards and inmates at Guantánamo have said that deaths which the US military called suicides at the time, were in fact homicides under torture. No murder charges have been brought for these or for acknowledged torture-related homicides at Abu Ghraib and at Bagram.

Hani Salih Hasan Hanjour (Arabic: هاني صالح حسن حنجور, romanized: Hānī Ṣāliḥ Ḥasan Ḥanjūr; 30 August 1972 – 11 September 2001) was a Saudi terrorist and a member of al-Qaeda who was the hijacker-pilot of American Airlines Flight 77, crashing the plane into the Pentagon as part of the September 11 attacks in 2001.

Hanjour first went to the United States in 1991, studying English for less than two months at an American higher education institution before returning to Saudi Arabia early the next year. He returned to the United States in 1996, studying English in California before he began taking flying lessons in Florida and then Arizona. He received his commercial pilot certificate in 1999, and went back to his native Saudi Arabia to find a job as a commercial pilot. Hanjour applied to civil aviation school in Jeddah, but was turned down. Hanjour left his family in late 1999, telling them that he would be traveling to the United Arab Emirates to find work. According to Khalid Sheikh Mohammed, Osama bin Laden or Mohammed Atef identified Hanjour at an Afghanistan training camp as a trained pilot and selected him to participate in the 11 September attacks.