Waterboarding interrogation techniques

Waterboarding is a coercive interrogation technique that U.S. officials, who have authorized its use against extremely resistant prisoners, state does not violate international agreements about torture. It has clear relationship to torture methods, used by various countries at various times, which depend on inducing an asphyxiation reflex; of the historical methods, some could cause actual asphyxia or other damage caused by water entering the lungs.

At least two variations have been described in U.S. use. According to ABC News' description of the version used by the Central Intelligence Agency, a plastic barrier covers the nose and mouth, and water is poured onto a cloth on top of the barrier. The barrier can block the airway, but it does prevent water from entering the respiratory tract. A "drowning reflex", however, appears to be triggered by the sensation of water flow coupled with airway restriction.

A variant method is described, in the U.S. Army memorandum requesting its use, is described as "use of a wet towel and dripping water to induce the misperception of suffocation." The description does not make it explicit if a barrier prevents the wet towel from admitting water to the respiratory tract, or if the cloth is in the throat, making it similar to the historic "Dutch technique".

Use of either method, by the CIA or Army, required specific prior approval by a senior U.S. official. According to ABC, the CIA approving official was the Deputy Director for Operations. Army approval authority varied from the commanding general of the Guantanamo Bay detention camp, to the commander of United States Southern Command, to the commander of the occupation force in Iraq (then CTF-7, later Multi-National Corps-Iraq).