Lawyers for the Obama administration, arguing for their ability to kill an American citizen without trial in Yemen, contended that the protection of US citizenship was effectively removed by a key congressional act that blessed a global war against al-Qaida.

Known as the Authorization to Use Military Force (AUMF), the broad and controversial 2001 law played a major role in the legal decision to kill Anwar al-Awlaki, the former al-Qaida propagandist and US citizen, in 2011, according to a redacted memorandum made public on Monday.



"We believe that the AUMF's authority to use lethal force abroad also may apply in appropriate circumstances to a United States citizen who is part of the forces of an enemy authorization within the scope of the force authorization," reads the Justice Department memorandum, written for attorney general Eric Holder on 16 July 2010 and ostensibly intended strictly for Awlaki's case.

Among those circumstances: "Where high-level government officials have determined that a capture operation is infeasible and that the targeted person is part of a dangerous enemy force and is engaged in activities that pose a continued and imminent threat to US persons or interests."

The 2nd US circuit court of appeals in Manhattan released the memo on Monday in response to a lawsuit from the American Civil Liberties Union and the New York Times.

The AUMF is unbounded by geographic or time limitations, indicating the wide berth the Obama administration provides for understanding its powers for the potential targeting of US citizens. The administration's official policy is that the AUMF ought to be "ultimately repeal[ed]", as Obama said in May. The administration does not support immediate repeal, which already faces a difficult congressional road.



Barely over a year after the memo was issued, Awlaki was dead, following a US drone strike – the first such lethal strike known to have deliberately targeted an American citizen. Yet an earlier US assault on Awlaki, in December 2009, predated the memo.



While Obama administration officials have for years insisted that Awlaki was an operational leader of al-Qaida in the Arabian Peninsula, which in 2009 and 2010 attempted unsuccessfully to detonate bombs inside the US, they have also fought lawsuits seeking to reveal their case against Awlaki.



But for the case against Awlaki, hinted at in a Justice Department "white paper" summarizing it that leaked last year, the administration leaned significantly on the broad leeway for counter-terrorism the AUMF established.



"Just as the AUMF authorizes the military detention of a US citizen captured abroad who is part of an armed force within the scope of the AUMF, it also authorizes the use of 'necessary and appropriate' lethal force against a US citizen who has joined such an armed force," reads the memo, written by former Justice Department lawyer David Barron, who also analyzed and rejected arguments that killing Awlaki would be tantamount to murder.



"It is true that here the target of the contemplated actions would be a US citizen," reads the memo.



"But we do not believe al-Aulaqi's citizenship provided a basis for concluding that section 1119 would fail to incorporate the established public authority justification for a killing in this case."

The release of the memo, as ordered Monday by a federal appeals court, ended a legal battle that has stretched for years, intended to prevent the administration from killing Awlaki or any other US citizen without trial. After losing an April appeal and confronting a challenge by Republican senator Rand Paul to deny Barron a federal judgeship, the Obama administration agreed not to fight the document's disclosure.

"The release of the legal memorandum follows the administration’s decision last month not to appeal the court’s decision. The material being released is consistent with the administration’s previous statements on this issue," said Justice Department spokesman Brian Fallon.



But its suppression challenge took various forms and arguments over the years, despite repeated official confirmations about the drone strikes, including from the president; despite the confirmed killing of four Americans, three of whom are claimed to have been killed accidentally, including Awlaki's 16-year-old son; and despite the 2013 leak of a memo summarizing the Justice Department's arguments about so-called "targeted killing" for Congress.



The redacted version of the memo released Monday does not reveal much of the factual basis for the government's claims that Awlaki represented an imminent threat to the United States.



In the disclosed portions, Barron's memo does not explicitly vouch for the government's case against Awlaki, referring instead to "the facts represented to us". It refers instead to Awlaki as a "leader" who was "continuously planning attacks" against the US, without providing an evidentiary basis for claims central to the extraordinary circumvention of normal due process procedures. Nor do the public sections explain why capturing Awlaki was not feasible, nor why the Justice Department believes it need not have provided Awlaki with judicial process.

The CIA, which along with the military's special operations forces sought authority for the strike, declined to comment. Barron was confirmed by the Senate to the federal bench on 22 May.



The Justice Department memo "confirms that the government’s drone killing program is built on gross distortions of law", said Pardiss Kebriaei, a lawyer with the Center for Constitutional Rights who challenged the Awlaki killing, who added that the "forced transparency comes years late".



Rejecting a government argument that the release of the memorandum would chill attorney-client communications, the court wrote on Monday: "If this contention were upheld, waiver of privileges protecting legal advice would never occur. … We need not fear that OLC will lack for clients."



Several of the government's appeals for secrecy have been overtaken by the public record, the court found. Among them: the "identity of the country in which al-Awlaki was killed", which was reported as being Yemen on the day of the lethal strike; and the involvement of the CIA, which in addition to being an open secret for years was confirmed by former director Leon Panetta.



"We recognize that in some circumstances the very fact that legal analysis was given concerning a planned operation would risk disclosure of the likelihood of that operation, but that is not the situation here where drone strikes and targeted killings have been publicly acknowledged at the highest levels of the Government," the court explained.

The ACLU, which sought along with the New York Times to compel the release of the memo, vowed to fight the government's additional arguments for secrecy around other legal foundations of what it calls its "targeted killing" program.



“We will continue to press for the release of other documents relating to the targeted-killing program, including other legal memos and documents relating to civilian casualties," said deputy legal director Jameel Jaffer.



"The drone program has been responsible for the deaths of thousands of people, including countless innocent bystanders, but the American public knows scandalously little about who is being killed and why.”



In May 2013, Obama raised his standards for launching drone attacks or other so-called "targeted" lethal military action against terrorist suspects. American drones struck last week in both Yemen and Pakistan, though no Americans are suspected of being killed.

US senator Ron Wyden praised the memo's release and called for more transparency on Monday. "For example, how much evidence does the president need to determine that a particular American is a legitimate target for military action? Or, can the president strike an American anywhere in the world? What does it mean to say that capturing an American must be ‘infeasible’? And exactly what other limits and boundaries apply to this authority?" he said.

"I urge the executive branch to build on today’s disclosure and start answering these additional questions."