Washington:
A New York court today released an edited version of a United States government memo legally justifying a drone attack that targeted and killed an American in Yemen in 2011.
Radical US-Yemeni cleric Anwar al-Awlaki was targeted and killed in the drone attack in September of that year. Samir Khan, who has dual Pakistani-US citizenship, died in the same attack.
Awlaki's teenage son, Abdul Rahman, was killed in a separate US drone strike in Yemen in October 2011. None of the three US citizens were ever charged with a crime.
The New York Times and two of its journalists had filed a lawsuit demanding the government make public secret papers justifying drone attacks against suspected terrorists, including American citizens.
The American Civil Liberties Union supported the Freedom of Information Act case.
The released July 16, 2010 legal memo from the US Department of Justice justified Awlaki's targeting on the grounds that he was an enemy leader whose capture in Yemen would have been "infeasible."
As a leader in Al-Qaeda in the Arabian Peninsula, his activities in Yemen posed "a continued and imminent threat" of violence to the United States, the memo said.
And, as an "active, high-level leader of an enemy force who is continually involved in planning and recruiting for terrorist attacks," Awlaki's killing would not be a war crime, it added.
The memo also said the cleric had been involved "in an abortive attack" in the United States and "continues to plot attacks intended to kill Americans" from Yemen.
His citizenship did not make him immune from being targeted abroad and the drone strike would "comply with international law," it said.
US drone strikes, a programme shrouded in much secrecy, has become a key tactic in America's war against suspected terrorists in Pakistan, Somalia and Yemen.
But human rights groups say the programme lacks clear legal limits.
US officials defend it as carefully regulated and one that has weakened Al-Qaeda's core leadership and reduced the threat of attack on American soil.
Washington today regards AQAP -- a merger of Al-Qaeda's Yemeni and Saudi branches -- as the terror group's most dangerous franchise and it has been increasingly targeted by drones.