The new “Authorization for Use of Military Force of 2018” (2018 AUMF) drafted by Senators Corker and Kaine is a long-overdue, serious proposal.  By its own terms, it aims to: (1) “reaffirm the domestic legal basis” for the “ongoing armed conflict against al Qaeda, the Taliban, and associated forces,” that “has evolved to include numerous non-state terrorist groups, including the Islamic State in Iraq and Syria (ISIS);” and (2) “reassert the role of Congress in authorizing and conducting oversight of the use of military force.”  These are worthy goals.  Presidents have been relying on the 2001 AUMF (and at times, the 2002 AUMF) to use force against an array of non-state armed groups, most of which did not exist in 2001, in numerous theaters around the world, for 17 years. A bipartisan proposal to repeal these authorizations and reassert Congress’s constitutional role in deciding whether and against whom to use military force abroad is welcome.

That said, if not tailored appropriately, Congress risks writing an even broader blank check for the President than the 2001 AUMF turned out to be—and hard-wiring a “global war on terror” that has no reasonable prospect of ending.  The 2001 AUMF authorized the President to use military force in response to an armed attack against the United States that triggered the right to act in self-defense.  In 2004, Justice O’Connor reasoned for a four-Justice plurality in Hamdi v. Rumsfeld that the powers “incident” to war under the law of armed conflict, such as the power to detain those captured on the battlefield, were included in Congress’s authorization because that conflict was, in essence, capable of being regulated by the law of armed conflict: there was a ground war in Afghanistan that could be expected to end at some point, terminating the war authorities that flow from the 2001 AUMF without further congressional action.  In marked contrast, the Corker-Kaine AUMF divorces the authorization to use force from the 9/11 attacks, or any other armed attack on the United States.  Instead, it embraces a quasi-permanent, multi-front war that will exist as long as the progeny of the groups that engaged in those attacks or the progeny of their “associated forces” continue to exist (as determined by the President).  Already, six of the eight groups against which the bill would explicitly authorize the use of military force did not exist on 9/11, and that’s before the bill’s open-ended mechanism for letting the President add new groups is considered.  In sum, unless this proposal is itself reined in, it could create a permanent framework for an ever-expanding, quixotic forever war with congressional imprimatur.  So is there a way to fix it?

To engage seriously with this proposal, we should ask the following four questions:

  • First, what is the purpose of a new AUMF? Reasserting Congress’ role (i.e., ensuring it is Congress who decides whether to use military force, not the President)?  Reining in the substantive scope of the war (i.e., stopping the President from asserting an unmoored, implied authority to use force against groups or in countries not actually authorized by Congress)?  Ensuring that our current conflicts all have statutory authorization?  Or some combination of these goals?
  • Second, what is the baseline of authority conferred on the President under existing authorizations, either explicitly in statutory text or implicitly, and how would the draft 2018 AUMF differ from the status quo?
  • Third, does the framework the 2018 AUMF creates for expanding the scope of the authorization over time (both as to new groups and new countries) retain enough power in Congress to be meaningfully different from current processes that operate outside of a procedural statutory framework? Or does the proposed framework give more authority to the President, even when Congress doesn’t act, by adding Congressional imprimatur to the President’s action? And in 2018, does Congress want to continue to sanction the practice of continuing to expand the scope of the conflict at all?
  • Fourth, and finally, if the draft 2018 AUMF does not, on balance, meaningfully reassert a role for Congress or constrain the scope of the conflict, what would a modified draft need to contain in order to be better than no new authorization at all?

Below I’ll assess the most contested elements of the draft 2018 AUMF (Professor Bobby Chesney has also provided a great overview at Lawfare) and offer alternatives for Congress to retain more of its authority vis-à-vis the President, constrain the scope of the conflict, or both.

  1. Substantive Scope of Authorization: the “against whom” question

Current Named Groups and “Associated Forces”  

The 2001 AUMF authorizes force against “those nations, organizations, or persons [the President] determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001, or harbored such organizations or persons….”  This has long been understood to refer to al Qaida (AQ), which planned and committed the 9/11 attacks, and the Taliban in Afghanistan, which “harbored” AQ at the time.  Despite the limiting language in the operative sentence stating force is authorized “in order to” prevent future acts of terrorism by “such” nations, organizations, or persons (i.e., by those described in the first half of that sentence), the Executive branch has long interpreted the 2001 AUMF to imply authorization to use force against “associated forces” of the described groups (such as al Qaida in the Arabian Peninsula, or AQAP), and more recently to successors of those organizations (i.e., the Islamic State of Iraq and the Levant, or ISIL).  The Executive Branch has publicly described the following four groups beyond AQ and the Taliban as within the scope of the 2001 AUMF: (1) The Haqqani Network; (2) AQAP; (3) Al Shabaab; and (4) ISIL, which is covered according to the Executive Branch because “at the time military action against the group now known as ISIL commence [sic] in 2003, that group was either part of, or an associated force of” AQ and the subsequent “rift” between AQ and ISIL “did not remove ISIL from coverage under the 2001 AUMF.”  In 2016, the Obama administration also stated that certain “individuals who are part of al-Qa’ida in Libya” are covered by the 2001 AUMF.

In a recent report to Congress, the White House declined to provide its view of the scope of the 2001 AUMF, referring instead to a classified annex available only to Congress, so we can’t be sure this is the full list of covered organizations according to the Executive Branch.  We do know that it differs significantly from the list of two primary groups long accepted as falling under the 2001 AUMF (only AQ and the Taliban).  And while Congress and lower courts have blessed the concept of “associated forces” in the context of the detention of non-citizens, neither has determined that each of these specific groups or individuals are as a factual matter “associated forces” within the scope of the 2001 AUMF.  That means the status quo is an Executive Branch claim that the 2001 AUMF confers authority to use force against this list of groups and individuals (and possibly others described in classified communications with Congress), without judicial or congressional imprimatur on that interpretation of existing authority.  The delta between the President’s claim of implied authorization and that which is explicitly described in statute or confirmed by courts at least leaves open whether the 2001 AUMF, on its own terms, confers authority as broad as that claimed by the President.

Draft 2018 AUMF

The 2018 AUMF would provide explicit congressional authorization to use force against six groups that are not described in the 2001 AUMF:  ISIL, AQAP, Al Shabaab, AQ in Syria (“including Al Nusrah Front”), al-Qa’ida in the Islamic Mahgreb (AQIM), and The Haqqani Network.  This moves a presidential claim of statutory authority for the use of force against these groups from a “grey” area of unilateral assertion based on implied authorization to solid ground.  And it would put to rest the controversial question of whether there is statutory authorization to use force against ISIL under the 2001 AUMF.  In addition, because ISIL is named as one of the primary groups against which force is authorized, and not as an associated force, the 2018 AUMF would create a statutory framework for explicitly authorizing the use of force against associated forces of ISIL – a logical extension of the broad theory embraced by the Obama and Trump administrations, but one that has been challenged by a number of members of Congress as stretching the 2001 AUMF too far (are associated forces of associated forces, none of which existed in 2001, also covered?).

If Congress passes an AUMF with this list of eight armed groups (five as associated forces), it will be blessing full-scale military operations against all of them in perpetuity – and that’s only a jumping off point for the President adding new associated forces and successor groups unless rejected by a veto-proof supermajority of both Houses (as explained further below).  This sure looks like codifying a “global war on terror.”


The first question for Congress is whether a new AUMF is needed because the substantive scope of the use of military force has expanded too far, stretching our military too thin or beyond theaters where we must operate by necessity, or whether the issue is that Congress’s role must be reasserted (presumably to avoid the President running away with implied authority), or both.  For members who believe the issue is not solely one of inter-branch Constitutional prerogatives but also that the scope of the current armed conflicts is too broad, this draft could be improved by taking a serious look at whether we should be at war with all of these groups (putting aside whether, under the Executive’s interpretation of the international law of armed conflict, we could be at war with them so long as Congress authorizes it).

This means first seriously examining where U.S. military force is not only lawful, but also the only or the best means of effectively and sustainably addressing a serious threat to the United States posed by non-state terrorist groups, or whether a combination of other tools of U.S. power – ranging from security sector assistance to intelligence and law enforcement cooperation to the use of multilateral diplomacy or sanctions to development assistance – would be sufficient or more effective than the use of military force.  It also entails examining whether the significant human and financial costs of military operations are worth whatever security gains might be realized.  The Corker-Kaine draft will be the appropriate starting point if the list is eight groups long (spanning six countries) at the end of that rigorous process.  But simply blessing what appears to be the Administration’s current list doesn’t seem to grapple with that hard set of decisions and policy trade-offs that would evince a true congressional reassertion of authority over choosing whether our nation should be at war. That is to say, do we really need an AUMF for all eight of these groups? If so, why?

  1. Process for New Associated Forces & Successors: the ever-expanding conflict 

Existing Process for Naming Associated Forces

There is currently no statutory process for deciding that a particular organized armed group is covered by the 2001 AUMF by virtue of its being an associated force, or successor, of AQ or the Taliban.  The Executive Branch determines through an internal process whether it believes additional entities or individuals are covered by the 2001 AUMF, and it is not required to publicly report who it believes to be covered.  There is no congressional role in this process, although the President is required to report new associated forces to Congress on a periodic basis.  However, as noted above, given Congress hasn’t explicitly stepped up to authorize force against these new groups and courts very rarely are presented with cases that would decide the issue on the merits, some ambiguity arguably remains as to the validity of the Executive’s unilateral associated forces determinations.  This ambiguity (among other factors) may serve as an internal constraint on Executive Branch decisions to determine that new groups are covered by the 2001 AUMF. 

Draft 2018 AUMF

The Corker-Kaine draft AUMF explicitly allows the President to designate new associated forces and requires any new designations to be reported to Congress within 48 hours.  For 60 calendar days following such a report, a resolution to remove the new group from the list will be entitled to expedited procedures.  If a vote on such a resolution were to be held and succeed, it would be subject to presidential veto.

This provides more transparency, more quickly, at least to Congress (the reports may be classified, so the public might not see them).  But it likely does not provide a meaningful check on presidential authority to expand the scope of the conflict.  Indeed, failure to reject a group would be construed – including by courts should litigation arise in the detention context – as a carefully constructed statutory scheme in which Congress will have implicitly approved use of force against the new group if not explicitly rejected by a veto-proof supermajority of both Houses (i.e., it would put the Executive’s claim of authority into the strong footing territory of Youngstown category 1, not category 2).  As Professor Bobby Chesney put it over at Lawfare (although with some skepticism that this would be the end result), it “overtly passes the decision-making buck to the White House.”  In practice, it may also remove the internal constraint on unilateral associated force determinations associated with the existing ambiguity of its unilateral pronouncements, because it provides a readymade pathway for congressional blessing of those determinations simply by virtue of congressional inaction.


There are a number of ways for Congress to retain more meaningful control over authorizing the use of military force against new groups.  First and foremost, if Congress wanted to robustly reassert its Constitutional role and ensure it does not write a blank check for a permanent state of war, a new AUMF could explicitly state that it does not authorize the use of force against “associated forces” beyond those named in the statute, and that the President must come back to Congress and seek authority to use force when necessary.

If a procedural mechanism to add new groups must be included, the presumption should be flipped: Congress should vote to add the newly designated group following a Presidential request (not to remove it following a Presidential designation).  If the presumption is not flipped, a vote to remove new groups should be required, not optional, which should at least force more meaningful Congressional consideration.  As a variant with tighter congressional control, a vote to approve a new group could be held within a certain timeframe but without expedited procedures, making it more akin to the normal process for authorizing the President to use force.   Finally, inclusion of a sunset (addressed below) would require Congress to vote on whether, and against whom, to remain at war, which could serve as a meaningful check on presidential determinations.  That said, as we’ve seen from recent proposals including this one, once the President claims groups are included, Congress may be reticent to exclude those groups going forward (if it continues to authorize force at all).

  1. Definition of Associated Forces: who is eligible for designation?

Current Associated Force Definition

The Obama administration defined “associated forces” based on a two-part test: “First, the entity must be an organized, armed group that has entered the fight alongside al-Qa’ida or the Taliban. Second, the group must be a co-belligerent with al-Qa’ida or the Taliban in hostilities against the United States or its coalition partners.”  The Trump administration has used the same test in the ongoing Doe v. Mattis litigation.  As noted above, Congress and the courts have also embraced the notion of “associated forces” (in codifying detention authority in 2012 and deciding habeas cases, respectively), although the application of this standard in practice remains unsettled.

Draft 2018 AUMF

The draft AUMF provides an even broader, two-part definition of “associated forces.”  The first part mirrors the Executive’s definition and thus codifies the rather broad status quo.  The second part seems intended to codify the theory under which ISIL was swept under the 2001 AUMF (although notably, the Executive did not call ISIL an “associated force” but rather a “successor”).  It states that “associated forces” include any “organization, person, or force, other than a sovereign nation,” that: “has been a part of al Qaeda, the Taliban, ISIS, or an associated force designated pursuant to this authorization and is engaged in hostilities against the United States or its coalition partners” (emphasis added).  The use of the past tense is likely intended to sweep in groups that have broken apart from named entities (sometimes referred to as “splinter groups”), even if those groups are hostile to those they broke away from (like ISIL and AQ).  Such groups are under any recognizable concept of international law not “co-belligerents” of AQ or the Taliban, so it’s interesting Corker and Kaine included them under the “associated forces” heading rather than creating a separate category (or excluding them altogether).


As noted above, Congress could choose not to create a procedural mechanism allowing the President to continually expand the scope of the conflict and could explicitly state that the use of force against new “associated forces” is not authorized.  But if Congress is going to create such a mechanism, the strained concept of “associated forces” could be dispensed with altogether.  It was employed in the Obama administration, and now by the Trump administration, largely to get around a pesky problem: the lack of explicit domestic statutory authorization to use force against groups not described in the 2001 AUMF.  This was done by resort to an ambiguous-at-best international law doctrine of “co-belligerency.”  In essence, those groups that satisfied a test purportedly drawn from international law for being co-belligerents (a term more or less synonymous in Executive branch parlance with “associated forces”) of the groups referenced in the domestic law authorization were treated as impliedly subject to that domestic statutory authorization as well.  (This is explained in depth in a fascinating and thoughtful article by Professor Rebecca Ingber.)

So what work is the concept of “associated forces” doing if there is a statutory process that will allow the President to bring new groups within the domestic authorization?  One could argue that it serves the purpose of tethering the use of force back to the 9/11 attacks because groups at least have to be associated forces, or successors, of those that committed the attacks.  But in reality, with groups as far removed from those attacks as, say, al Shabaab already included, we should acknowledge that naming new “associated forces” that aren’t already listed is essentially delving into new conflicts (despite the international law rationale continuing to rest on their relationship back to AQ).  Arguably, the primary remaining value of using the term at all is that it ensures that only groups that can lawfully be targeted with military force under international law are brought within the domestic authorization.  But there are better ways to do this than resorting to the strained and vague concept of co-belligerency.

First, we should continue to acknowledge (as the Supreme Court did in Hamdi) that “necessary and appropriate” force is that which is consistent with international law – this draft AUMF already uses that language.  Second, Congress could state clearly, rather than through the “necessary and appropriate” language alone, that the President must comply with the international law on the resort to force (jus ad bellum) and the international law on the conduct of hostilities (jus in bello) in any use of force authorized by the new AUMF.  Finally, as a variant of a suggestion by Professor Ingber, Congress could require a certification, made jointly by the Secretaries of State and Defense, that the new group is an “organized, armed group” as that term is understood in international law and that there is an international legal basis for the use of military force against the newly designated group, with a report explaining that legal basis.  (To be sure, the Executive will argue that, with respect to the named “associated forces,” the legal basis is their “co-belligerency” with one of the primary groups.  Congress would then decide whether to embrace the theory of co-belligerency and the factual claims that sweep a particular group in, or whether to limit their authorization to those groups that have actually engaged in an armed attack against the U.S. or present an imminent threat of doing so.)

  1. Geographic Scope: the “where” question

Current Geographic Scope

The Executive branch has long held that the 2001 AUMF does not have geographic limitations and has resisted proposals that would reduce its potential global reach.  It argues that international law, in particular territorial sovereignty, does place meaningful limits on where force can be used (although employing the “unable or unwilling” theory under which force can be used against non-state actors within another state without that state’s consent has put some pressure on the claim of limited legal authority).

Draft 2018 AUMF

The Corker-Kaine draft AUMF starts by authorizing the use of force in six countries (Afghanistan, Iraq, Syria, Somalia, Yemen, and Libya), and creates a process for authorizing force in additional countries.  Similar to the associated force designations, the President is required to report whether force is being used in any additional countries within 30 days and to report to Congress within 48 hours if he begins using force in any country beyond the six identified.  For the following 60 days, a resolution to remove the new country would be entitled to expedited procedures.


As with the process for adding new groups, there are a number of ways for Congress to retain greater control over where the President uses military force, starting with flipping the presumption such that a vote is required to add new countries, rather than to remove them.  Given the consequences of using force in a new country and the potential for embroiling the U.S. in an international armed conflict, Congress should also require the Secretary of State to certify that there is an international legal basis for the use of force against non-state actors within that country and provide that legal basis in the required report (rather than solely requiring a report on the “military objectives, persons, or forces targeted” within the new country as in the Corker-Kaine draft).

  1. Sunset: for how long should we be at war, against a potentially expanding list of armed groups, before Congress weighs in again?

Current Expiration 


Draft 2018 AUMF

The Corker-Kaine draft does not sunset.  It does provide for more congressional debate on the continued use of military force and the scope of its authorization than the 2001 AUMF.  Specifically, it requires a “quadrennial review” by the President and allows for expedited consideration of resolutions to modify or repeal the AUMF every 4 years.


In order to preserve a meaningful role for future Congresses and prevent the accretion of Presidential power by Congressional inaction, the new AUMF should sunset in 4 years.  Congress can reauthorize force just as it reauthorizes other extraordinary authorities, and a decision not to do so should be taken seriously.  As Rosa Brooks, Sarah Cleveland, Jennifer Daskal, Walter Dellinger, Harold Hongju Koh, Ryan Goodman, Marty Lederman, and Steve Vladeck persuasively argued several years ago, the function of a sunset clause “is not to terminate the campaign before it has achieved its objectives, but instead to ensure that Congress affirmatively decides whether and under what terms to continue to support the evolving nature of the conflict, consistent with its historical and constitutional role.”  They also noted precedent for sunsetting an AUMF: the 1983 authorization for Lebanon, which lasted for 18 months unless Congress extended the timeline.

Failing inclusion of a sunset, a new AUMF should at minimum require a vote on whether terminate the authorization (as opposed to a vote to continue) every 4 years.  If the vote fails, the AUMF remains in force.  But this would at least put all members on record as to whether they want to continue to authorize the armed conflict or not and provide an incentive for Congress to play a robust oversight role in the interim.  Short of such a forcing mechanism, Congress has too many incentives to continue shirking its responsibility to decide whether the United States should use military force and against whom—and, even if it doesn’t, the President could veto any effort to actually assert that authority.


Unfortunately, the Corker-Kaine AUMF as drafted doesn’t succeed at meaningfully reining in the President or the scope of the conflict, which it unmoors from any armed attack against the United States and sets on a footing for permanent expansion.  To be sure, it creates more transparency than under existing force authorizations and provides structure for congressional debate.  It also arguably reasserts Congress’ role in deciding the scope of the conflict at the moment of passage if not in the future – albeit by deferring essentially entirely to the President’s existing interpretation of his implied authority.  But at bottom, it creates a far greater substantive scope of authority to use force than explicitly included in any existing authorization.  And procedurally, it confers tremendous power on the President to wage war against new groups and in new countries under a framework with Congressional imprimatur, unless Congress affirmatively steps up and votes by a veto-proof majority to dial that authority back, a highly unlikely prospect.  If Congress truly wants to reassert its role in authorizing military force, which I strongly believe it should do, it should not hand the President the permanent authority to expand the conflict unless a veto-proof supermajority can be mustered to stop him.

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