I go to bed at night worrying that I didn't do enough that day to make sure I protect the American people.

The actions that we take on the counterterrorism front, again, are to take actions against individuals where we believe that the intelligence base is so strong and the nature of the threat is so grave and serious, as well as imminent, that we have no recourse except to take this action that may involve a lethal strike.

Unfortunately, in war, there are casualties, including among the civilian population.

John O. Brennan Quotes