Earlier today, a group of legal experts–including Rosa Brooks, Sarah Cleveland, Jen Daskal, Walter Dellinger, Harold Koh, and Marty Lederman–released a set of “Principles to Guide Congressional Authorization of the Continued Use of Force Against ISIL.” As two of the drafters of these Principles, we wanted to elaborate upon their content. But we also wanted to write on our own behalf (and speaking only for ourselves) to explain why we believe each of these six Principles is an essential element of any legislation Congress intends to consider—and potentially adopt—on the subject.

Although our group identified six Principles, the two of us believe they can be broken down into three general categories: (1) constraints; (2) consistency; and (3) accountability.

I.  Constraints

The first three Principles are all designed to properly cabin whatever authority Congress sees fit to provide, to ensure that the force Congress authorizes in an ISIL-based AUMF is calibrated to the specific threat ISIL poses to the United States and U.S. interests. To that end, we explain that, consistent with historical practice, any new AUMF should (1) be ISIL-specific and mission-specific; (2) include geographic limits; and (3) include a sunset provision.

Each of these constraints vindicates two distinct—yet related—values: avoiding unnecessary wars and preserving democratic accountability. By having an ISIL-specific AUMF clearly identify both the enemy and the mission, Congress will focus America’s attention—and energy—on those threats that, at the present moment, cannot adequately be quelled through existing means, including law enforcement and self-defense tools. As the Principles emphasize, “Congress should not preemptively authorize force against as-yet unknown enemies.” To similar effect, geographic limits (like those contained in Senator Tim Kaine’s draft AUMF) will prevent an ISIL-specific AUMF from being invoked for uses of force in theaters far removed from and unrelated to the current armed conflict. And a sunset provision will ensure that, however the conflict evolves in the coming weeks and months, Congress and the American public will have a voice in revisiting and revising its scope and objectives as those months turn into years.

To be sure, the first two of these sets of constraints are the source of the greatest daylight between our Principles and other proposals for new AUMFs—such as that outlined in the Hoover Institution white paper co-authored by Bobby Chesney, Jack Goldsmith, Matt Waxman, and Ben Wittes. But insofar as avoiding unnecessary wars and preserving democratic accountability should be the goals of any legislation authorizing the use of military force, we believe that such constraints are essential.

II.  Consistency

The fourth and fifth Principles are designed more to reconcile an ISIL-specific AUMF with existing use-of-force authorizations. To that end, the fourth Principle explains why an ISIL-specific AUMF should come alongside repeal of the 2002 Iraq AUMF and a sunset provision for the September 2001 AUMF. With regard to the 2002 Iraq AUMF, an ISIL-specific AUMF would moot any further need for this increasingly vestigial conflict, which already provided at best a marginal justification for any use of force in contemporary Iraq. Lest the preservation of the 2002 statute allow for an end-run around the more specific limits that the Principles provide for an ISIL-specific AUMF, the need for its repeal is manifest.

With regard to the September 2001 AUMF, again, the concern driving the Principles is that “enacting a new AUMF without revisiting existing force authorization statutes could lead to a debilitating state of perpetual war, confusing legal authorities, and diminished congressional oversight.” Especially insofar as the 2001 AUMF has already been invoked as the basis for at least some uses of force against ISIL, providing that it should be revisited on the same schedule as an ISIL-specific AUMF further serves the twin goals of avoiding unnecessary wars and preserving democratic accountability.

The fifth Principle—ensuring that U.S. uses of force are consistent with international law—is to similar effect. Indeed, this is one of the most important points of overlap between the Principles and proposals such as the Hoover Institution paper. As Bobby, Jack, Matt, and Ben wrote:

[A]ny statutory reform in this area should emphasize compliance with jus in bello and jus ad bellum . . . . [A]cknowledging clearly that U.S. operations are to be conducted within, rather than beyond, traditional legal frameworks is an important step in mitigating friction with our allies, and prudent use of these legal authorities will be important in persuading allies that the U.S. position is a reasonable one.

We couldn’t have said it better ourselves.

III.  Accountability

Finally, the sixth Principle is targeted directly at democratic accountability. It requires a commitment by the Executive Branch to transparency with respect both to facts and legal analysis. To the former, the Principles require bi-annual reports from the President to Congress “(1) describing the progress toward the mission’s objectives; (2) identifying any groups or nations other than ISIL that have joined the armed conflict; and (3) providing detailed information about civilian and combatant casualties on all sides.” And to the latter, the Principles call upon the President to share with Congress, and, insofar as it’s practicable, the American people “any significant legal analyses regarding the scope of, and legal authority for, U.S. uses of force.” Especially in conjunction with the sunset provisions the Principles urge for both the 2001 AUMF and the ISIL-specific AUMF, such transparency is essential to provide the relevant decision-makers with the necessary information when it comes time to revisit those authorities. Simply put, these pieces all fit together to produce a force regime most precisely and responsibly tailored to the current threat.

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We hope that the Principles will help inform deliberations about the proper scope of congressional authorization for uses of force against ISIL. And more fundamentally, we hope—and believe—that these Principles strike the appropriate balance between the need to respond to the threat posed by ISIL and the importance of avoiding unnecessary wars and preserving democratic accountability in the process.