Two of the Predator drones pointed lasers on the trucks to pinpoint the targets, while the larger Reapers took aim and fired. And for the first time since the Civil War, the United States government had carried out the deliberate killing of an American citizen as a wartime enemy and without a trial. http://www.nytimes.com/2013/03/10/world/middleeast/anwar-al-awlaki-a-us-citizen-in-americas-cross-hairs.html?hp&_r=0  Then came the unclassified Justice Department “white paper” summarizing the administration’s abstract legal arguments that were prepared months after the Awlaki  killing.  The missile strike on Sept. 30, 2011, that killed Mr. Awlaki also killed Samir Khan, another American citizen who had moved to Yemen from North Carolina, though officials had judged he was not a significant enough threat to warrant being specifically targeted. The next month, another drone strike mistakenly killed Mr. Awlaki’s 16-year-old son, Abdulrahman, who had set off into the Yemeni desert in search of his father. A missile apparently intended for an Egyptian Qaeda operative, Ibrahim al-Banna, hit a modest outdoor eating place in Shabwa. The intelligence was bad: Mr. Banna was not there, and among about a dozen men killed was the young Abdulrahman al-Awlaki, who had no connection to terrorism and would never have been deliberately targeted. The damage was only compounded when anonymous officials at first gave the younger Mr. Awlaki’s age as 21, prompting his grieving family to make public his birth certificate.He had been born in Denver, said the certificate from the Colorado health department. In the United States, at the time his government’s missile killed him, the teenager would have just reached driving age. Within just two weeks, the American government had killed three of its own citizens in Yemen. Only one had been killed on purpose. Mr. Awlaki presened himself as a moderate bridge-builder, he gave interviews to the national news media, preached at the Capitol in Washington and attended a breakfast with Pentagon officials.

The Constitution generally requires judicial process before the government may kill an American and there is a statute that bars Americans from killing other Americans overseas. In light of the gravity of the question and with more time, they began drafting a second, more comprehensive memo, expanding and refining their legal analysis and, in an unusual step, researching and citing dense thickets of intelligence reports supporting the premise that Mr. Awlaki was plotting attacks.

There was the two-part Harvard Law Review essay in 2008 concluding that the Bush team’s theory of presidential powers that could not be checked by Congress was “an even more radical attempt to remake the constitutional law of war powers than is often recognized.” Then senator, Mr. Obama had called the Bush theory that a president could bypass a statute requiring warrants for surveillance “illegal and unconstitutional.”

A 1994 crime bill,  makes no exception on its face for national security threats. By contrast, the main statute banning murder in ordinary, domestic contexts is far more nuanced and covers only “unlawful” killings. This was divorced from its original context and misunderstood as a general statement about the scope and limits of the government’s authority to kill citizens, the free-floating reasoning would lead to widespread confusion. Other problems to the theory included a disastrous American missile strike in May 2010 accidentally killed a deputy provincial governor in Yemen and infuriated President Saleh. Then, in August 2010, Mr. Awlaki’s father, with help from civil liberties groups, filed a lawsuit in Washington challenging the government plan to kill his son, which had been reported in the news media. The US invoked the state secrets privilege and in December 2010, a judge dismissed the suit. Then attacks allegedly linked in various ways to Mr. Awlaki continued to mount, including the attempted car bombing of Times Square in May 2010 by Faisal Shahzad, a naturalized American citizen who had reached out to the preacher on the Internet, and the attempted bombing by Al Qaeda in the Arabian Peninsula of cargo planes bound for the United States that October. American and Saudi spies had turned a number of militants into sources.