From federal judge Colleen McMahon, after acknowledging that disclosure of the government's legal justification for targeting American citizens for assassination might help the public "understand the scope of the ill-defined yet vast and seemingly ever-growing exercise in which we have been engaged for well over a decade, at great cost in lives, treasure, and (at least in the minds of some) personal liberty":
However, this Court is constrained by law, and under the law, I can only conclude that the Government [...] cannot be compelled by this court of law to explain in detail the reasons why its actions do not violate the Constitution and laws of the United States. The Alice-in-Wonderland nature of this pronouncement is not lost on me; but after careful and extensive consideration, I find myself stuck in a paradoxical situation in which I cannot solve a problem because of contradictory constraints and rules — a veritable Catch-22. I can find no way around the thicket of laws and precedents that effectively allow the Executive Branch of our Government to proclaim as perfectly lawful certain actions that seem on their face incompatible with our Constitution and laws, while keeping the reasons for their conclusion a secret. But under the law as I understand it to have developed, the Government's motion for summary judgment must be granted, and the cross-motions by the ACLU and the Times denied.
Needless to say, Congress could change this if it wanted to. Apparently it doesn't.