Sen. Rand Paul (R-Ky.), in opposing the nomination to the U.S. Court of Appeals for the First Circuit of David Barron, the former Justice Department lawyer who wrote the drone memo analyzing the president’s power to kill Americans who have taken up with al-Qaeda, declared last month: “I’ve read David Barron’s memos concerning the legal justification for killing an American citizen overseas without a trial or legal representation, and I am not satisfied. While the President forbids me from discussing what is in the memos, I can tell you what is not in the memos. There is no valid legal precedent to justify the killing of an American citizen not engaged in combat. In fact, one can surmise as much because the legal question at hand has never been adjudicated. Therefore, I shall not only oppose the nomination of David Barron, but will filibuster.”

Sen. Rand Paul (R-Ky.) speaks at the 40th annual Conservative Political Action Conference in National Harbor, Md., on March 14, 2013. (Manuel Balce Ceneta/Associated Press)

On Monday, Barron’s 42-page memo was declassified and released, with some redactions. There actually is a whole lot of justification for the president to, for example, use a drone to kill Anwar al-Awlaki, the cleric who served as a recruiter and inspiration for terrorists including the Fort Hood murderer. One can disagree with his legal analysis — although I would be curious what precisely in the 42 pages Paul finds to be in error — but to declare that there isn’t any justification or that there is no precedent is flat-out wrong.

The Post reported:

Awlaki’s relationship with al-Qaeda “brings him within the scope” of the 2001 congressional authorization of the use of military force, according to the document. Citing information provided by the CIA and Pentagon, the memo said Awlaki has “operational and leadership roles” with al-Qaeda and “continues to plot attacks intended to kill Americans.”

In part because that authorization specified no geographic boundaries, it did not matter that Awlaki was based in Yemen rather than Afghanistan, where the bulk of the U.S. war effort against al-Qaeda was focused.

The memo explores a range of other potential legal issues, finding, for example, that federal laws designed to prevent U.S. nationals from getting away with murder overseas “had nothing to do with the conduct of an authorized military operation by U.S. armed forces.” . . .

The newly released document indicates that both the U.S. military and the CIA had assured the Justice Department that “they intend to capture” Awlaki but had made clear that doing so “would be infeasible at this time.”

While acknowledging that killing a U.S. citizen carries “the risk of erroneous deprivation of a citizen’s liberty in the absence of sufficient process,” the memo argued that those considerations are overwhelmed when the target poses “a continued and imminent threat of violence or death” to other Americans.

Moreover, there is ample precedent going back to World War II to treat U.S. collaborators with the enemy as enemy combatants.

Benjamin Wittes, an expert on the law of war (but by no means a cheerleader for untrammeled executive authority), further explained that the constitutional issues were covered in a separate Office of Legal Counsel memo, but then the just-released memo “retreads this subject,” albeit with some redactions:

[The] memo embraces a Mathews v. Elbridge balancing test for its Fifth Amendment analysis. And it concludes that “a decision-maker could reasonably decide that the threat posed by al-Aulaqi’s activities to United States persons is ‘continued’ and ‘imminent’. . . .” Both agencies had said they didn’t regard his capture as feasible, though they intended to capture him if it were so. The memo concludes that there is no Fifth Amendment barrier to an operation “at least where, as here, the target’s activities pose a ‘continued and imminent threat of violence or death’ to U.S. persons, ‘the highest officers in the Intelligence Community have reviewed the factual basis’ for the lethal operation, and a capture operation would be infeasible—and where the CIA and DoD ‘continue to monitor whether changed circumstances would permit such an alternative’. . . .”

Similarly, the memo rejects Fourth Amendment barriers to the operation, applying a similar balancing test found in Tennessee v. Garner and Scott v. Harris. Even in domestic law enforcement, Barron notes, where an officer has probable cause that a suspect poses a threat of serious physical violence either to the officer or to others, it is constitutionally reasonable to prevent escape using lethal force. “In the present circumstances . . . the U.S. citizen in question has gone overseas and become part of the forces of an enemy with which the United States is engaged in an armed conflict; that person is engaged in continual planning and direction of attacks upon U.S. persons from one of the enemy’s overseas bases of operations; the U.S. government does not know precisely when such attacks will occur; and a capture operation would be infeasible.” Under such circumstances, the use of lethal force, the memo concludes, is not unreasonable and would not violate the Fourth Amendment.

In short, if we start with the broad powers in Article 2 of the Constitution authorizing the president to wage war, add in the Authorization for Use of Military Force (AUMF) and satisfy both due process and Fourth Amendment concerns, you have a pretty compelling legal justification for using a drone to kill an American jihadi plotting against the United States.

It is noteworthy that the American Civil Liberties Union did not attack the memo’s substance nor allege that there was a paucity of legal reasoning. To the contrary, its spokesman was pleased that the argument could be laid out and then be the topic of informed debate. On that I agree entirely, although a number of conservatives have expressed concern about how narrowly Barron interpreted the president’s powers. Let a thousand constitutional debates bloom. (To a large extent they already have, and white papers, legal panels and blog posts abound on the topic.)

It would seem that those opposing use of drones in these situations have an obligation to explain why. Do they, for example, not believe as a factual matter that Awlaki and other Americans are directly engaged with terrorists conducting a worldwide jihad against the United States? If so, that would be news. Do they think the AUMF doesn’t allow the president to kill enemies abroad who have taken up with al-Qaeda affiliates, contrary to its language? Again, the theory would be novel. But at bottom the “precedent,” if you will, is the Constitution itself, Article II, Section 2: “The President shall be commander in chief of the Army and Navy of the United States, and of the militia of the several states, when called into the actual service of the United States.”

At any rate, the memo highlights the degree to which politicians who oppose anti-terrorist measures — including the National Security Agency surveillance program, use of drones and detention of enemy combatants at Guantanamo Bay, Cuba, who cannot be tried in the United States (for evidentiary and other reasons) — have failed to make the legal case against these programs in concrete terms or have glossed over relevant case law (e.g. Supreme Court precedent holding only the contents of calls not the data about them is covered by the Fourth Amendment). Now, a politician is perfectly entitled to make a policy case against these items and some have (e.g. it is better to capture than kill American jihadists), but it is quite another to assert that these vital anti-terror measures are beyond the scope of the president’s power, even when authorized by Congress. This represents a serious diminution of executive power and would in the face of threats like a potential ISIS-controlled state severely hamper our ability to defend the homeland.

Here’s a proposal for anyone seeking a House or Senate seat or certainly the presidency: They should lay out specifically what anti-terror procedures they would discontinue and why, citing the concrete legal justification, if any, for their objection. That is the least they can do when they are proposing to tie the hands of the chief executive and Congress in an era when another 9/11 attack launched from ISIS territory is entirely conceivable. They should also spell out what sort of AUMF we will need after troops leave Afghanistan. None? One that covers the plethora of al-Qaeda and Iran-backed threats? Then Americans can judge for themselves who is responsible on national security and who is not.