The Legality of President Obama’s “Red Line” on Syrian Chemical Weapons

by Julian Ku

New evidence that Syria has used chemical weapons against insurgents have spurred new calls here in the U.S. for military action in Syria.  Here is the LA Times (hardly an interventionist paper):

An American or multilateral response should of course be proportional to the offense. That means considering whether chemical weapons were used against civilians or militants, and whether a “whole bunch” were used, as Obama put it, or much less. But there’s no doubt that an operation to secure or destroy the regime’s chemical weapons would be consistent with this country’s stated commitment (one that all too often has not been honored) to protect civilians from the worst ravages of war.

The editorial was plainly drafted carefully with some knowledge of the legal issues that would apply to such an operation.  First of all, there is that pesky U.S. Constitution, Article I, Section 8 which many folks think grants the the U.S. Congress the exclusive power to authorize U.S. military force.  I don’t think the editorial envisions President Obama seeking congressional authorization, so it is probably assuming he would act under his inherent Commander-in-Chief powers. (When George W. Bush was president, newspapers like the LA Times used to worry about the unilateral exercise of this type of power, but these days, not so much.)

Second, there is the international law governing the use of force. I raised this question back in December, when President Obama drew his red line, suggesting that the self-defense justification under the U.N. Charter can’t work here.  This post drew two very good responses from experts in the field, one from Daniel Bethlehem (formerly the chief legal advisor to the UK’s Foreign Office) and the other from Ashley Deeks (former legal advisor to the U.S. State Department, now UVA Law Prof).

My earlier post offered a simple no-frills reading of the U.N. Charter, building on the simple no-frills reading of the U.N. Charter critics of the Iraq War were fond of making in the Bush years. This was a useful strawman, since I pointed out it would lead to a “silly result.”  Still, I am not totally sold on the more sophisticated rationales offered by Daniel and Ashley.  As far as I know, Syria has not threatened (at least recently) to attack its neighbors. I don’t count its skirmishes with Turkey, which seem in any event to have settled down. It has certainly not threatened use of chemical weapons against Turkey, Israel, or anyone other than the Syrian rebels.  I am just not buying self-defense here, unless we really are back in 2002 and President Bush’s doctrine of preemptive self-defense for WMDs has achieved international consensus.

What is it about chemical weapons that changes the legal calculus? Sure, I realize the use of chemical weapons here is a plain and blatant violation of the law of armed conflict, and really horrible in every way possible.   But as horrible as it is, I wonder why chemical weapons would be the trigger since the casualties from the non-chemical weapons in Syria has been much worse. And what is it about chemical weapons that would per se justify humanitarian intervention, while the mass bombings or killings of thousands of civilians would not?

I am guessing the answer here is going to come from a different path that has nothing (formally) to do with chemical weapons.  Since the U.S. has recognized the Syrian opposition as the legitimate government of Syria, I suppose consent for an intervention can be had without too much trouble. But, this opposition doesn’t exactly have widespread recognition, and doesn’t really control most of the country. Still, it probably is the least difficult legal path.

When President Obama said using chemical weapons would “cross a red line,” he must have had something in mind, unless it was a total bluff.  A unilateral U.S attack is very possible, and may even be desirable.  But legality is going to have to be finessed in ways that critics of the Iraq War should not be happy with.

11 Responses

  1. Doesn’t Syria’s belligerent status vis a vis Israel, it’s facilitating of arms and terror operations against Israel through agents or directly count as a “threat to attack its neighbors”?  What chemistry is at work here?

  2. Despite what “many folks think”, Article I, Section 8 of the US Constitution grants Congress the power to “declare War”, not to “authorize U.S. military force”. It does not say that even that is “exclusive”.
    The distinction has been recognized since the adoption of the Constitution. George Washington, and virtually every President since, has used military force without a declaration of war and generally without authorization from Congress. 

  3. Recognition as the “legitimate representative of the Syrian people” is emphatically not the same as recognition as the Government of Syria. The U.S. very pointedly has not recognized a successor government to the Assad regime, in large part to make clear that Assad remains responsible for upholding Syria’s international obligations with regard to nonproliferation and human rights.

  4. A short article of mine, Use of Military Force in Syria by Turkey, NATO, and the United States, 34 U. Pa. J. Int’l L. _ (2012) is at the printers and should be out soon.  Of course, it answers any questions that one might have! ho ho, but it is highly relevant. Section 3.1 has a subtitel: Future Elimination of Chemcical and Biological Weapons in Syria.  And 3.2 has a title: Future U.S. Support of a Legitimate Government of the Syrian People.
    Also, my study (article) on constitutionally-based presidential power to use force in Libya is available at
    The primary basis of authority is Article II, Section 3 of the Constition, the duty (and concomitant competence) of the President to faithfully execute the Laws, which include  customary and treaty-based international law

  5. Anon: you are correct, but the matter is far more complex.  A “people” has a right to self-determination, not a government.  “The” govt. begs the question at stake, and it is possible to consider that the old regime still has a govt. but is merely one actor in Syria and, perhaps, merely a belligerent.  It is possible to claim that such a belligerent still has responsibilities under int’l law.  It is certainly possible to conclude that the old regiime is no longer the legitimate govt. of Syria, esp. under Univ. Dec. H.R. art. 21(3) and major developments in the law of self-determination.  It is possible for the legitimate rep. of the people of Syria to request aid that would be considered to be self-determination assistance and/or collective self-defents (since self-defense under customary int’l law is not merely a right of a state or a “govt.”).  Certainly, international law has never been merely state-to-state — see
    see the article above re: constitutionally-based prsidential power re: Libya and another article that is at the printers re: the Arab Spring —

  6. I think that Julian, and Deborah further above, are quite right to suggest that there are a host of legal problems in the assertion that the U.S. could intervene in Syria in the event that it is determined to have crossed the “red-line” of using chemical weapons. And as Julian suggests, creative efforts to provide legal justifications for such an intervention by those who were critical of the invasion of Iraq and the Bush doctrine, do tend to create an unfortunate sense of inconsistency at best.

    The fact remains that unless and until there is a real and imminent threat of armed attack against some other state, the justifications based on collective self-defense are simply not available. (and it certainly cannot rely on the pretext of Syria’s belligerent status with Israel to suddenly, after decades of living with that situation, to use force against Syria, as was suggested in the comments above – on that logic the U.S. could use force against Russia on the theory that it is still technically at war with Japan). Nor is the argument that the U.S. can intervene on behalf of the opposition because it has recognized it as the representative of the people, or a belligerent in the armed conflict, solve the problems created by the traditional jus ad bellum prohibitions on intervention in a civil war.

    That leaves humanitarian intervention, which of course everyone understands is a so-called emerging norm that has yet to actually crystallize into a customary international law. And as Julian and Deborah point out, even if it were a legal justification for intervention, the limited use of Sarin doesn’t magically change the analysis under this principle, since over 60,000 people have already been killed by conventional means. There is little principled basis for this red-line of chemical weapons use per se. The threat of wide-spread chemical weapons use that could impact Israel or Turkey is one thing, possibly grounding a self-defense argument, but the notion that a finding that Sarin has been used in limited fashion should trigger an intervention is hard to understand.
    In passing, it is not of course correct to claim that every President since George Washington has used force without Congressional approval – indeed, while it has become more common since the Korean war, perhaps ironically both George H. and George W. Bush sought and obtained Congressional approval before using force against Iraq. Nor is the claim of John Yoo et al, that the war powers provision of the Constitution has become an irrelevant anachronism in an age in which wars are not commenced by declaration, the dominant view. There is of course a vociferous debate on the issue. But equally accepted is the contrary argument that since declaring war, and issuing letters of marque and reprisal, were the recognized means of commencing and legally authorizing the use of force in the 18th century when the provision was drafted, it should be interpreted today as requiring Congressional approval of executive decisions to use force or commence armed conflict. There has, of course, been considerable criticism of the Obama administration’s position on the use of force in Libya in the absence of such approval. 

  7. –collective self-defense would be in connection with a request for assistance by the legitimate rep. of the people of Syria.  That could also fit within self-determination assistance.
    –Israel’s claim might be that when such weaponry is about to be controlled by Hezbollah, Israel can target the weaponry since there is continued armed conflict involved.
    –another collective self-defense claim might involve Turkey, since turkey has been under attack by military forces of the belligerent/remnant of the prior regime.

  8. recall that in March Pres. Obama announced another “red line” for the U.S. — if Iran attempts to create or acquire a nuclear weapon.
    Obama’s “red lines” might keep us busy.

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