Brennan at CIA fills 3rd key national security

John Brennan took over Friday as CIA director, the finishing touch on President Barack Obama\'s national security team for his second term, AP reported. The White House said Vice President Joe Biden swore Brennan in during a private ceremony a day after he won Senate confirmation amid a contentious debate that included one Republican senator\'s 13-hour speech in an effort to delay a vote. Republicans lifted their delay after the administration bowed to their requests for clarification about the president\'s power in using drone strikes. Brennan joins Chuck Hagel, who won Senate confirmation to be defense secretary, and Secretary of State John Kerry as Obama advisers on security. Brennan, a 25-year CIA veteran, had been Obama\'s top counterterrorism adviser. He replaces Michael Morell, the deputy director who had been in charge since David Petraeus resigned in November after acknowledging an affair with his biographer.