The U.S. military has at least three times in recent weeks engaged in hostilities against pro-Syrian regime forces near the At Tanf garrison in southern Syria and shot down a pro-regime drone in the same region on June 8.  In the first of these instances, Secretary of Defense Jim Mattis referred to the pro-regime forces more specifically as “Iranian-directed forces.”  After the second of these two incidents, U.S. Central Command (CENTCOM) released a “Coalition Statement on Actions near At Tanf, Syria,” describing what it refers to as a “deconfliction zone” established by the United States within Syrian territory.  “The Coalition does not seek to fight Syrian regime or pro-regime forces,” it states, “but remains ready to defend themselves if pro-regime forces refuse to vacate the de-confliction zone.”

The escalating trend of hostilities between the U.S. military and pro-regime forces is deeply concerning.  It raises the specter of a full-blown war among powerful militaries in Syria–between the United States and its partners on one side, and Syria, Russia, and Iran and their partners on the other.  This is not an exaggeration.  In the second exchange of fire, it was reported that “the US-supported forces also were forced to pull back when they were attacked by Russian aircraft.”  In a region already devastated by years of brutal conflict, the security and humanitarian implications are evidently grave.

From a purely legal standpoint, the recent U.S. military actions against pro-regime forces also raise immediate and serious questions.  The United States’ domestic and international legal footing in Syria must be addressed before we stumble further into the Syrian civil war, with the potential consequence of turning it into an international armed conflict.  Putting aside the somewhat murky issue of “unit self-defense” that arises when U.S. forces are defending themselves under fire or against a clear hostile intent, it is the actions of the United States that come before that point that must be examined.  Specifically, the United States purports to have carved out a swath of territory within Syria’s borders for use as a training ground (the so-called “deconfliction zone”) in its fight against the Islamic State of Iraq and the Levant (ISIL) and is using military force to expel pro-regime forces from that zone and its vicinity.  This raises the following questions: is taking and holding Syrian territory sought by the Syrian regime and its allies lawful?  And if so, what are the limits of action the United States can take against pro-regime forces under its theory of self-defense against ISIL?  As a domestic law matter, has Congress authorized the use of force against the Syrian regime, its allies Russia and Iran, and their non-state proxies, or is the Trump Administration acting unilaterally?

The policy questions regarding whether the United States should enter this war are many, to say the least, and must be saved for another day.  But the answers to these primarily legal questions also matter for our democracy:  we should not slide into a war without a clear and defensible legal basis, under domestic and international law, and Congress must not abdicate to the Executive its imperative constitutional responsibility of making “the hard decision to go to war.” 

A Complex Context

The battlespace in Syria has long been messy, at best.  In the conflict against ISIL, the U.S. military is leading a coalition of state and non-state actors in attempting to dislodge and defeat the terrorist group.  Actors outside of the U.S.-led coalition are also engaged against ISIL in Syria, to varying degrees of intensity, including Iranian-backed militias, Russian forces, and of course the Syrian regime itself.  The U.S. military has sought to avoid battlefield entanglement in a second conflict raging in Syria – the longer-running civil war against the Assad regime that began out of popular uprisings in 2011 – and the Obama Administration did not claim that it had authority under international law to engage in that civil war on the side of the opposition.  When the Trump Administration decided to bomb a Syrian government airfield on April 7, 2017, supposedly “to prevent and deter the spread and use of deadly chemical weapons,” it did so in a seemingly isolated attack, disconnected from any broader diplomatic or military strategy, without consulting Congress, and without offering legal justification.

The more the ongoing conflicts in Syria overlap in geography, in the actors participating, and importantly, in the territorial or other strategic aims of those actors, the harder it will be for the U.S. military to maintain the line operationally between participating in one (against ISIL) while generally avoiding the other (against Assad and his allies).  Indeed, the recent U.S. strikes on pro- regime actors in the At Tanf vicinity make this not just a future hypothetical, but a present danger.  A complex legal question is now squarely presented:  can the U.S. military lawfully take and hold Syrian land not only against ISIL, but also against pro-regime forces who have the lawful goal of regaining control over all of Syria’s territory?  There are both domestic law and international law questions that must be addressed in this context, including by our democratic representatives.

Domestic Law Questions

First, is there a valid basis under U.S. domestic law for the U.S. military, and its partners, to take and hold Syrian territory against pro-regime forces?  The Obama Administration made clear that it interpreted the 2001 Authorization for Use of Military Force (AUMF), in combination “in certain circumstances” with the 2002 AUMF (primarily authorizing intervention in Iraq), as providing domestic legal authorization for the use of military force against al-Qa’ida and ISIL in Syria.  However, it did not publicly take a position as to whether this statutory authority would extend to taking and holding territory sought by pro-regime forces within Syria, and if so, under what circumstances doing so would be authorized.  While this issue arguably should have been addressed earlier in the conflict against ISIL, it is indisputably now ripe.

The Trump Administration must make clear whether it believes its latest actions against pro-regime forces are covered by the 2001 and/or 2002 AUMFs, or whether Trump believes he is acting unilaterally, on his Constitutional authority alone, in striking pro-regime forces in these circumstances.  If the latter, the administration also should make clear – and Congress should be asking – whether the War Powers Resolution’s 60-day clock is triggered by these escalating incidents, particularly given CENTCOM’s warning that the At Tanf garrison “will not be vacated until ISIS is defeated.”  Congress should seek answers to these questions and subject them to debate before a full-blown international armed conflict develops in Syria, not after.

International Law Questions

As a matter of international law, the Obama Administration publicly and clearly explained its position that the “United States is using force in Syria against ISIL and providing support to opposition groups fighting ISIL in the collective self-defense of Iraq (and other States) and in U.S. national self-defense.”  Under the international law of self-defense, the United States may take only such action that is “necessary and proportionate” to address the threat posed by ISIL.  As has been the subject of much debate, the Obama Administration argued it could use force against ISIL within Syria in the absence of consent from the Syrian government because “Syria is unable or unwilling to confront effectively the threat that ISIL poses to Iraq, the United States, and U.S. partners and allies.”

The Trump Administration must make clear whether, and if so why, it believes that the principles of self-defense, including its “unable and unwilling” theory, which have been applied in the counter-ISIL context in Syria, extend so far as to permit the use force against pro-regime forces seeking control of Syria’s own territory.

A number of important subsidiary questions need to be addressed here, including the following non-exhaustive list as a starting point:

  • Why does the Trump Administration believe that it is both “necessary” and “proportionate” in the fight against ISIL to create territorial zones within Syria from which it may use force to expel all comers, including Syrian government-aligned actors?  Note that CENTCOM is using the term “deconfliction zones” although it is not clear why “deconfliction” is an apt concept in this context.
  • Does it matter that CENTCOM states it is using this territory for training purposes? What would the implications be if any non-state actors being trained at the garrison are or have been involved not just in the counter-ISIL fight but also the counter-Assad fight?
  • What reasonably available alternative means of addressing the threat posed by ISIL, if any, were explored before reaching the conclusion that creating a “deconfliction zone” within Syrian territory is a “necessary” and “proportionate” use of force?
  • Has the Trump Administration updated and reaffirmed the Obama Administration’s analysis that “the Syrian Government … cannot and will not confront ISIL effectively”?
  • If the Administration has not updated the analysis, how often must an unable or unwilling analysis be reviewed? For example, should a new analysis be conducted when new actors are involved in the conflict, new theaters are at issue, or when the nature or location of the enemy changes?

Congress and the American people need clear answers to these critical questions, as well as a range of imperative policy and strategy questions not addressed here.  In a theater where Russia and Iran are militarily engaged on behalf of the territorial government, and where military confrontations between the United States and these powers or their proxies are already occurring, the stakes of marching forward without addressing these questions are too high.


Image: Coalition and partnered forces repair At Tanf water well capable of supplying more than 317,000 gallons of water daily – U.S. Army photo