Obama has chosen a man who was at the heart of Bush's intelligence effort to play a key role in overseeing the new administration's own interrogation policies: John Brennan, a 25-year CIA veteran who was privy to the extreme tactics Obama has declared off limits. The White House refused to discuss Brennan's exact role in the new interrogation policy. But a former CIA official familiar with the situation said Brennan - Obama's top counterterrorism adviser - will head up a National Security Council team overseeing a new Justice Department interrogation corps, specifically chosen to interrogate the most important terror detainees. This isn't the first time Brennan has drawn controversy. When Brennan's name was floated as a leading candidate for CIA director during Obama's transition, liberal activists loudly questioned the possible choice, and Brennan later withdrew. Brennan himself has defended his role in an administration that has repeatedly distanced itself from the Bush-era tactics - saying he objected to the use of waterboarding on terror suspects, both in his time at the CIA and today. . . Several former CIA officials said Brennan, a former senior aide to CIA director George Tenet and later head of a national center to coordinate intelligence, was clearly in the loop when the so-called Enhanced Interrogation Techniques were approved in 2002. At the time, Brennan served as the CIA's deputy executive director.