The Justice Department released in 2003 a legal memo which gave authority to use the so-called harsh interrogation techniques against the suspected terrorists, the Pentagon said.

The memo released on March 14, 2003, came at a time when the Pentagon was trying to establish the approximate limits for its interrogators. The memorandum released by the Justice Department gave the Pentagon pretty much the same authority it had provided to the CIA in a similar memo issued a few months earlier.

Both memos were later annulled by the Justice Department.

The memo underlines the legal justification for the military to use harsh interrogation techniques on the al-Qaida and Taliban detainees. The memo wrote by John Yoo, then the deputy assistant attorney general for the Office of Legal Counsel, also specifies that the U.S. president’s wartime power as commander in chief will not be hindered by eventual U.N. treaties against torture.

"Our previous opinions make clear that customary international law is not federal law and that the president is free to override it at his discretion," said the memorandum.

"Finally, even if the criminal prohibitions outlined above applied, and an interrogation method might violate those prohibitions, necessity or self-defense could provide justifications for any criminal liability," was written in the memorandum regarding a possible charge brought against interrogators who violated U.S. or international laws.

Although many were aware of the memo’s existence, the fact that the 81-page opinion written by John C. Yoo was publicly released ads to the tension that surrounds the debate about legal boundaries in the face of a continuing terrorist threat.

The 2003 memorandum underlines the legal foundation used by the Bush administration after the Sept. 11 attacks on New York’s World Trade Center Towers to give the Pentagon broad powers to counter the terrorists. Some argue that these extensive powers led to abuses, especially at the detention center in Guantanamo Bay, Cuba.

The most controversial interrogation techniques used by the CIA to deal with hardened terrorists who have been trained to resist the methods mentioned in the U.S. Army Field Manual handbook are waterboarding, sensory deprivation, temperature extremes, extended forced standing.