From left, National Security Agency Director Adm. Mike Rogers, former FBI Director James Comey, former Director of National Intelligence James Clapper, ex-CIA Director John Brennan, and Defense Intelligence Agency Director Lt. Gen. Vincent Stewart participate in the Senate intelligence committee's hearing on worldwide threats last year. Alex Brandon/AP hide caption
CIA Director John Brennan at CIA headquarters on Thursday. Ariel Zambelich/NPR hide caption
CIA Director John Brennan. Andrew Harnik/AP hide caption
CIA Director John Brennan discussed ISIS, the FBI-Apple dispute over an iPhone, the state of the Iran nuclear deal, and his future plans as President Obama's term draws to a close. Ariel Zambelich/NPR hide caption
CIA Director John Brennan listens during a news conference at CIA headquarters in Langley, Va., in December 2014. Pablo Martinez Monsivais/AP hide caption
CIA Director John Brennan Carolyn Kaster/AP hide caption
Senate Majority Leader Harry Reid faces reporters on Capitol Hill in Washington on March 11, following a caucus lunch. J. Scott Applewhite/AP hide caption
Sen. Dianne Feinstein speaks to reporters after speaking about her oversight committee's problematic relationship with the CIA Tuesday. CIA Director John Brennan says his agency isn't trying to delay the panel's report on the U.S. interrogation program. Mark Wilson/Getty Images hide caption
The seal of the CIA at the agency's headquarters in Virginia. Greg E. Mathieson Sr./MAI/Landov hide caption
Sen. Rand Paul, R-Ky., during his filibuster. Senate Television/AP hide caption
John Brennan, President Obama's nominee to head the CIA, prepares to testify at his confirmation hearing before the Senate Intelligence Committee on Thursday. J. Scott Applewhite/AP hide caption
John Brennan, President Obama's nominee to be the next CIA director, worked closely with Saudi Arabia to set up a secret U.S. drone base there, The New York Times reported. Brennan's confirmation hearing is Thursday. Kevin Dietsch/UPI /Landov hide caption
John Brennan, President Obama's nominee to be the next CIA director. Kevin Dietsch/UPI /Landov hide caption