142 children, in drone strikes in Pakistan that targeted 24 people successfully and unsuccessfully, and, in numerous failed attempts to kill Ayman al-Zawahri, 76 children and 29 adults were killed. Estimates for the total people killed in U.S. drone strikes in Pakistan, range from 2,000–3,500 militants killed and 158–965 civilians killed. 81 insurgent leaders in Pakistan have been killed. Drone strikes in Yemen are estimated to have killed 846–1,758 militants and 116–225 civilians. 57 Al-Qaeda in the Arabian Peninsula leaders are confirmed to have been killed Obama administration position on combat drones In a speech titled "The Ethics and Efficacy of the President's Counterterrorism Strategy" John O. Brennan, Assistant to the President for Homeland Security and Counterterrorism, outlined on 30 April 2012 at the Wilson Center the use of combat drones to kill members of al-Qaeda by the US Federal government under President Barack Obama. John Brennan acknowledged for the first time that the US government uses drones to kill selected members of al-Qaeda. He justified the use of drones both from domestic law and international law point of view. With respect to domestic law Brennan stated, "as a matter of domestic law, the Constitution empowers the President to protect the nation from any imminent threat of attack. The Authorization for Use of Military Force (AUMF) passed by Congress after the 11 September attacks authorizes the president "to use all necessary and appropriate force" against those nations, organizations and individuals responsible for 9/11. There is nothing in the AUMF that restricts the use of military force against al-Qa'ida to Afghanistan." And he further said: "As a matter of international law, the United States is in an armed conflict with al-Qa'ida, the Taliban, and associated forces, in response to the 9/11 attacks, and we may also use force consistent with our inherent right of national self-defense. There is nothing in international law that bans the use of remotely piloted aircraft for this purpose or that prohibits us from using lethal force against our enemies outside of an active battlefield, at least when the country involved consents or is unable or unwilling to take action against the threat." The speech came a few days after Obama authorized the CIA and the U.S. Joint Special Operations Command (JSOC) to fire on targets based solely on their intelligence "signatures"—patterns of behavior that are detected through signals intercepts, human sources and aerial surveillance, and that