When can the president order the execution without trial of an American citizen? The New York Times recently reported that in June 2010, the Justice Department’s Office of Legal Counsel produced a secret fifty-page legal memo that sought to answer that question, and authorized President Obama to order the killing of Anwar al-Awlaki, a US citizen living in Yemen and a leader of al-Qaeda in the Arabian Peninsula (AQAP).

In September, the US carried out that order with a drone strike that killed al-Awlaki and another US citizen traveling with him. Two weeks later, the US also killed al-Awlaki’s son, reportedly “collateral damage” in a separate drone attack in Yemen. Al-Awlaki himself was afforded no notice, no charges, no trial. As far as we know, no one outside the executive branch reviewed the President’s decision. The strike was front-page news, and apparently was undertaken with the approval of Yemeni authorities, yet since it was a “covert operation,” the Obama administration has declined even to acknowledge that it ordered the killing. The President did, however, call a news conference to announce that al-Awlaki “was killed,” and to proclaim his death a “success [that] is a tribute to our intelligence community.”

So now we know that there is a secret memo that authorized the secret killing of a US citizen—but both the memo and the killing remain officially “secret” despite having been reported on the front page of The New York Times. Whatever one thinks about the merits of presidents ordering that citizens or noncitizens be killed by remote-controlled missiles, surely there is something fundamentally wrong with a democracy that allows its leader to do so in “secret,” without even demanding that he defend his actions in public.

Indeed, some have drawn parallels to the secret memos that Justice Department lawyers John Yoo, Jay Bybee, and Stephen Bradbury wrote during the Bush administration to provide legal cover for the CIA’s torture and cruel and inhuman treatment of suspects who had been abducted and “disappeared” into secret prisons. Then as now, the Office of Legal Counsel, a part of the Justice Department charged with giving legal advice to the president, developed extensive legal memos to justify conduct that would have been unthinkable before September 11. Then as now, the merits of the legal positions advanced were deeply controversial. And then as now, secrecy served to deflect public scrutiny of tactics that many Americans might well reject if the issues were fully aired.

There are important differences, to be sure. Inflicting cruel or inhuman treatment on wartime captives is never permissible. Torture is absolutely prohibited, in war as well as peace. By contrast, it is not illegal to kill enemy fighters…