The legality of targeted killing of suspected terrorists, including U.S. citizens, was examined in a memorandum prepared for members of Congress by the Congressional Research Service.

The U.S. practice of targeted killing raises complex legal issues because it cuts across several overlapping legal domains. To the extent that the U.S. is actually at war with the targeted persons, the “law of armed conflict” would provide the appropriate legal framework, though the relevance of this framework far from a “hot battlefield” is disputed. Outside of armed conflict, the U.S. could be acting under the related but distinct laws of “self-defense.” The use of lethal force in law enforcement operations offers another way of conceiving of and evaluating anti-terrorist strikes. In all cases, the sovereignty of the nation where the strike occurs adds a further layer of legal complexity. With respect to targets who are U.S. citizens, the applicability of the U.S. Constitution is yet another urgent issue.

Obama Administration officials have discussed targeted killing in several public speeches since 2010, but have evaded detailed public questioning on the subject. The Justice Department Office of Legal Counsel has prepared a memorandum on the targeting of suspected terrorists who are U.S. citizens, as reported by the New York Times, but it has refused to release the OLC memorandum or even to publicly acknowledge that it exists. Meanwhile, Congress has been largely silent and acquiescent.

The CRS memorandum, entitled “Legal Issues Related to the Lethal Targeting of U.S. Citizens Suspected of Terrorist Activities,” was prepared in May 2012 by legislative attorney Jennifer K. Elsea. It presents an overview of the pertinent legal context, and then carefully parses official Administration statements in an attempt to infer a detailed legal rationale for lethal targeting. A copy was obtained by Secrecy News.

“This memorandum is an effort to clarify the debate by providing legal background, setting forth what is known about the Administration’s position and identifying possible points of contention among legal experts and other observers,” the memo states.

In the end, CRS concludes that none of the established legal frameworks is a perfect fit for the Administration’s lethal targeting operations because the current U.S. practice of lethal targeting involves features that are improvised, inconsistent or otherwise questionable.

For example, CRS says the Administration appears to have redefined the meaning of “imminence,” one of the required elements for justifying the use of force in self-defense on the territory of another country. The standard definition of imminence refers to an overwhelming threat that allows “no moment for deliberation.” But the Administration uses imminence idiosyncratically “to refer to the window of opportunity for striking rather than the perceived immediacy of the threat of an armed attack.” This novel usage “may pose some challenge to the international law regarding the use of force,” CRS said.

The CRS memo notes that the U.S. Supreme Court has ruled — in Hamdi v. Rumsfeld — that when a U.S. citizen is detained as a suspected enemy combatant he must be given notice of the factual basis for his detention and an opportunity to rebut it. Yet, in contrast, when a citizen-suspect is to be killed rather than detained the Administration’s position is that no such notice or opportunity is required.

This embrace of unchecked executive authority may prove difficult to reconcile with the majority holding in Hamdi, the memo suggests.

In fact, CRS says, the Administration’s position “seems to conform more with Justice Thomas’s dissenting opinion in Hamdi, in which Justice Thomas argued that in the context of wartime detention for non-punitive purposes, ‘due process requires nothing more than a good-faith executive determination’.”

By withholding its own Office of Legal Counsel opinion on the legality of lethal targeting of suspected terrorists who are U.S. citizens, the Obama Administration seems intent not on protecting sensitive operational details but on suppressing public awareness and debate. The CRS memo is not a substitute for the OLC opinion, but it nonetheless can serve to advance public understanding of the underlying issues.