The CIA have added Anwar al-Awlaki, the American citizen implicated in both the Nidal Hassan Fort Hood shooting and the failed underwear bombing on Christmas Day, to a capture-or-kill list of terrorist threats. Awlaki, born in New Mexico, required a special government review through the National Security Council to place him on the list, by virtue of him being a US citizen.

Awlaki is believed to be the first U.S. citizen the CIA has been given authorization to kill or capture since 2001. The U.S. military keeps a separate list of individuals it is permitted to capture or kill. Awlaki’s name was already on that list.

U.S. officials say that Awlaki has helped transform Yemen’s Al Qaeda offshoot into the terrorist network’s most active affiliate outside Pakistan and Afghanistan.

So there are two lists, one from DoD and one from CIA. But it’s an open question whether the US could put any citizen on a target list for assassination, and the White House isn’t showing their work. This has alarmed civil liberties advocates, who say this goes beyond even John Yoo’s conception of executive power.

In June 2002, John Yoo, then a lawyer for the Justice Department’s Office of Legal Counsel, assessed that U.S. citizenship was no obstacle to the government detaining a suspected terrorist and providing him with a trial before a military commission. “[T]he President’s authority to detain an enemy combatant is not diminished by a claim, or even a showing, of American citizenship,” Yoo wrote. But even Yoo did not consider the more radical claim of stripping American citizenship from a suspected terrorist for the purpose of legally killing him; and President Obama formally annulled Yoo’s memorandum in an executive order within days of taking office.

The White House claims that it has enough evidence to indicate that Awlaki is collaborating with Al Qaeda in an operations capacity, but they haven’t shown that evidence to the public, nor have they provided a legal rationale. As Spencer Ackerman says today, “if citizenship means anything, it means that a citizen can’t be killed because the government uses secret evidence to say he or she is an intolerable threat.” Obviously, investing this kind of power in an executive to make extra-judicial life and death decisions is a slippery slope. So Spencer’s filing FOIA requests to see the legal basis for putting Awlaki on the capture-or-kill list.

Meanwhile, Jeralyn Merritt muses that Awlaki may have moved from Yemen to Somalia with the rest of the Al Qaeda in the Arabian Peninsula leadership.