The CIA used an arsenal of severe interrogation techniques on Al Qaeda prisoners for nearly seven years without seeking a rigorous assessment of whether the methods were effective or necessary, according to current and former U.S. officials familiar with the matter.

The failure to conduct a comprehensive examination occurred despite calls to do so as early as 2003. That year, the agency's inspector general circulated drafts of a report that raised deep concerns about the use of waterboarding and other methods, and recommended a study by outside experts on whether those techniques worked.

More...