The Obama administration on Monday reluctantly released its justification for killing an American citizen, Anwar al-Awlaki, whom it considered a terrorist, in a 2011 drone strike in Yemen. But the rationale provides little confidence that the lethal action was taken with real care.

Under orders from a federal appeals court, the Justice Department made public a 2010 memo explaining why the drone strike was legal. Considering how long the administration fought the release, which was sought by The New York Times and the American Civil Liberties Union, one might have expected a thoughtful memo that carefully weighed the pros and cons and discussed how such a strike accords with international and Constitutional law.

Instead, the memo turns out to be a slapdash pastiche of legal theories — some based on obscure interpretations of British and Israeli law — that was clearly tailored to the desired result. Perhaps the administration held out so long to avoid exposing the thin foundation on which it based such a momentous decision.

The main theory that the government says allows it to kill American citizens, if they pose a threat, is the “public authorities justification,” a legal concept that permits governments to take actions in emergency situations that would otherwise break the law. It’s why fire trucks can break the speed limit and police officers can fire at a threatening gunman. But it’s a dangerous concept if expanded because it could be used to justify all kinds of government misdeeds, especially since Congress has never explicitly authorized an exception for official killing in this kind of circumstance, as the memo acknowledges.