Justifying the use of remotely piloted aircraft, a top Obama administration counter terrorism official said that "rigorous standards" were applied in these attacks which were carried out in "surgical manner" and "laser like precision."
Marking the anniversary of the killing of al-Qaeda founder Osama Bin laden by American special forces in Pakistan, John Brennan, President Obama's top counter-terrorism adviser told a meeting here that the strikes were used only in cases of "significant threat."
He described al-Qaeda as "legitimate military target" which was in armed conflict with the US "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," Brennan said in his address to international scholars at Woodrow Wilson Centre.
This is the first time that US has made public an elaborate explanation of drone strikes which have sharply increased in places like Pakistan and Yemen with the emergence of new technology- which reduces the cost and risks of open warfare.
Brennan said the President had directed officials to be more open about how they decide to kill terrorism suspects. "These targeted strikes are legal," he asserted.
"To briefly recap, as a matter of domestic law, the Constitution empowers the President to protect the nation from any imminent threat of attack," the US official said.
"The Authorisation for Use of Military Force -- the AUMF -- passed by Congress after the September 11 attacks authorises the President 'to use all necessary and appropriate force' against those nations, organisations and individuals responsible for 9/11.
There is nothing in the AUMF that restricts the use of military force against al-Qaeda to Afghanistan," he said.