Yes, the attack on Syria was justifiable, and international law will benefit from it
Russian Premier Vladimir Putin has declared the U.S.’s strike on a Syrian airbase in the aftermath of the chemical weapon attack on civilians a violation of international law. Some U.S. politicians and scholars seem to agree with him. I believe, however, that because the strikes were so focused and limited, they are legally justifiable, and certainly do not establish a carte blanche for military intervention anywhere and everywhere. To the extent a new norm may be emerging, it is one that reinforces international law. Allow me to explain.
The facts as the U.S. sees them
Let’s start by laying out the facts as the Pentagon reports them (I’ve added some embedded links not included in the Pentagon’s release):
At the direction of the president, U.S. forces conducted a cruise missile strike against a Syrian Air Force airfield today at about 8:40 p.m. EDT (4:40 a.m., April 7, in Syria). The strike targeted Shayrat Airfield in Homs governorate, and was in response to the Syrian government’s chemical weapons attack April 4 in Khan Sheikhoun, which killed or injured hundreds of innocent Syrian people, including women and children.
The strike was conducted using Tomahawk Land Attack Missiles (TLAMs) launched from the destroyers USS Porter and USS Ross in the Eastern Mediterranean Sea. A total of 59 TLAMs targeted aircraft, hardened aircraft shelters, petroleum and logistical storage, ammunition supply bunkers, air defense systems, and radars. As always, the U.S. took extraordinary measures to avoid civilian casualties and to comply with the Law of Armed Conflict. Every precaution was taken to execute this strike with minimal risk to personnel at the airfield.
The strike was a proportional response to Assad’s heinous act. Shayrat Airfield was used to store chemical weapons and Syrian air forces. The U.S. intelligence community assesses that aircraft from Shayrat conducted the chemical weapons attack on April 4. The strike was intended to deter the regime from using chemical weapons again. Russian forces were notified in advance of the strike using the established deconfliction line. U.S. military planners took precautions to minimize risk to Russian or Syrian personnel located at the airfield.
We are assessing the results of the strike. Initial indications are that this strike has severely damaged or destroyed Syrian aircraft and support infrastructure and equipment at Shayrat Airfield, reducing the Syrian Government’s ability to deliver chemical weapons. The use of chemical weapons against innocent people will not be tolerated.
According to the President, he ordered the attack because it “is in the vital national security interest of the United States to prevent and deter the spread and use of deadly chemical weapons.” In addition, he said:
Years of previous attempts at changing Assad’s behavior have all failed and failed very dramatically. As a result, the refugee crisis continues to deepen, and the region continues to destabilize, threatening the United States and its allies. (Emphasis added).
Secretary of State Rex Tillerson and National Security Advisor LTG H.R. McMaster confirmed at a news conference last night that the deadly chemical used was sarin, and that there was “very high confidence” that it was the Syrian government forces that used it. (The Russians argue otherwise.)
Tillerson mentioned Syria’s violation of UN Security Council Resolution (UNSCR) 2118, the 2013 agreement whereby Syria was supposed to destroy its chemical weapon stocks. He further observed:
I think the other thing that it’s important to recognize that as Assad has continued to use chemical weapons in these attacks with no response – no response from the international community – that he, in effect, is normalizing the use of chemical weapons, which may then be adopted by others. So it’s important that some action be taken on behalf of the international community to make clear that the use of chemical weapons continues to be a violation of international norms. (Emphasis added).
Tillerson also said that “one of the existential threats we see on the ground in Syria is, if there are weapons of this nature available in Syria, the ability to secure those weapons and not have them fall into the hands of those who would bring those weapons to our shores to harm American citizens.” He claimed that “the response from our allies as well – in Europe as well as in the region in the Middle East has been overwhelmingly supportive of the action we’ve taken.” He said the President chose an option that “was clearly directed at the source of this particular attack to send that strong message.” Tillerson reiterated his concern about the threat “these type of weapons [presented by] falling into [terrorist] hands and being brought to our shore [as being] a direct threat on the American people.” (Emphasis added.)
For his part, LTG McMaster made it clear that the “targets that were associated with the ability of that airfield to operate and continue mass murder attacks against Syria’s – the Syrian civilians.” In addition, he said that measures were put in place to avoid hitting places where the sarin gas was stored, “so that that would not be ignited and cause a hazard to civilians or anyone else.”
In terms of international law, the use of force against another nation is generally forbidden by Article 2 (4) of the UN Charter. There are two main exceptions to the prohibition. First, a Security Council resolution authorizing the use of force under Chapter 7 of the UN Charter would legalize an attack. But UNSCR 2118 referenced by Secretary Tillerson did not itself authorize the use of force in the event of noncompliance and, in any event, there is no chance that the Security Council would authorize the use of force because Syria’s ally Russia would exercise its veto power.)
The second possible grounds for lawfully using force is self-defense. Article 51 of the UN Charter provides:
Nothing in the present Charter shall impair the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations, until the Security Council has taken measures necessary to maintain international peace and security. Measures taken by Members in the exercise of this right of self-defence shall be immediately reported to the Security Council and shall not in any way affect the authority and responsibility of the Security Council under the present Charter to take at any time such action as it deems necessary in order to maintain or restore international peace and security.
Despite the horrific nature of the attack on the Syrian civilians, international law usually does not permit the U.S. or any nation from acting in self-defense of foreign nationals in their country absent a request from their own government. This is one of the lessons of the 1986 Nicaragua case where the International Court of Justice did not accept as lawful the claim that U.S. actions against Nicaragua were acts in collective self-defense of El Salvador against rebels supported by Nicaragua. Essentially, this means we cannot ordinarily act in self-defense of Syrians against their own government.
We can, however, act in self-defense of our own citizens. Although Article 51 reads as if the armed attack would already need to have occurred, there is a broadly-accepted concept known as anticipatory self-defense. This principle of international law is rooted in an 1841 incident involving the destruction by the British of the steamer Caroline that was involved in aiding Canadian rebels. Then Secretary of State Daniel Webster declared that a nation can act anticipatorily when the “necessity of self-defence [is], instant, overwhelming, leaving no choice of means, and no moment for deliberation.” Essentially, this means there must be an imminent threat.
The United States and several other countries have taken a broad view of what constitutes an imminent threat under international law. Late last year the Obama Administration issued what it called a “Report on The Legal and Policy Frameworks Guiding the United States’ Use of Military Force and Related National Security Operations.” Here’s what it said about how imminence is determined (footnotes omitted):
When considering whether an armed attack is imminent under the jus ad bellum for purposes of the initial use of force against another State or on its territory, the United States analyzes a variety of factors. These factors include “the nature and immediacy of the threat; the probability of an attack; whether the anticipated attack is part of a concerted pattern of continuing armed activity; the likely scale of the attack and the injury, loss, or damage likely to result therefrom in the absence of mitigating action; and the likelihood that there will be other opportunities to undertake effective action in self-defense that may be expected to cause less serious collateral injury, loss, or damage.” Moreover, “the absence of specific evidence of where an attack will take place or of the precise nature of an attack does not preclude a conclusion that an armed attack is imminent for purposes of the exercise of the right of self-defense, provided that there is a reasonable and objective basis for concluding that an armed attack is imminent.” Finally, as is now increasingly recognized by the international community, the traditional conception of what constitutes an “imminent” attack must be understood in light of the modern-day capabilities, techniques, and technological innovations of terrorist organizations.
The requirements of the law, and especially the way the US interprets imminence, may explain why the President said that Syria’s use of chemical weapons was “threatening the United States and its allies” and that “prevent[ing] and deter[ing] the spread and use of chemical weapons is vital [to the] national security interest of the United States.” Similarly, Secretary Tillerson’s referenced the danger to Americans that the existence of these weapons in a chaotic place like Syria represented because they could fall into the hands of “elements on the ground in Syria” who are “plotting to reach our shore.” This amounted, he says, to a “direct threat on the American people.”
When President Obama was threatening military action against Syria in 2013 for using chemical weapons, the notion of self-defense – anticipatory or otherwise – was deemed by most scholars as factually insufficient. Michael Schmitt pointed out at the time that there was no indication that Syria intended to attack the U.S., and further insisted that even “contagious instability does not rise to the level of an armed attack such that the affected States may employ force in self-defense.”
Schmitt agreed that the prospect of chemical weapons falling into the hands of terrorists (as Tillerson discussed in the current context) presented a “colorable” threat to the U.S. and its allies, but concluded that the imminence requirement was not met. According to Schmitt, the Assad regime had not yet “lost control of the country to the point where it is probable that the weapons will fall into the hands of terrorist groups.”
However, since that time, Syria has only fallen into further chaos, so a reasonable person could conclude that Assad no longer has enough control over the weapons to obviate the danger of their loss. Moreover, what is also quite different today from 2013 is the fact that the U.S. reportedly has over 500 troops in Syria. I believe the physical proximity of these U.S. troops to both Assad’s forces and terrorist fighters makes the case for an imminent threat to Americans significantly stronger.
Besides a Security Council action or a self-defense justification, there is another, albeit controversial, legal grounds for using force, but one which may have special applicability here. In 2013 Harold Koh, a State Department Legal Advisor during the Obama Administration, argued that prohibitions on the use of force absent one of the traditional authorities (UNSC approval or self-defense) was “overly simplistic” and that “international law has evolved sufficiently to permit morally legitimate action to prevent atrocities by responding to the deliberate use of chemical weapons.” He contends that the broader purposes of the UN Charter were served in such situations, and offered limiting criteria:
 If a humanitarian crisis creates consequences significantly disruptive of international order— including proliferation of chemical weapons, massive refugee outflows, and events destabilizing to regional peace and security of the region– that would likely soon create an imminent threat to the acting nations (which would give rise to an urgent need to act in individual and collective self-defense under Article 51);
 a Security Council resolution were not available because of persistent veto; and the group of nations that had persistently sought Security Council action had exhausted all other remedies reasonably available under the circumstances, they would not violate U.N. Charter Article 2(4) if they used
 limited force for genuinely humanitarian purposes that was necessary and proportionate to address the imminent threat, would demonstrably improve the humanitarian situation, and would terminate as soon as the threat is abated.
In particular, these nations’ claim that their actions were not wrongful would be strengthened if they could further demonstrate:
 that would prevent the use of a per se illegal means by the territorial state, e.g., the use of banned chemical weapons; or
 that would help to avoid a per se illegal end: e.g., war crimes, crimes against humanity, or an avertable humanitarian disaster, such as the widespread slaughter of innocent civilians, e.g., another Halabja or Srebrenica.
Any credible legal analysis would need to substantiate each factor with persuasive factual evidence: (1) Disruptive Consequences likely to lead to Imminent Threat; (2) Exhaustion, (3) Limited, Necessary, Proportionate and Humanitarian Use of Force; (4) Collective Action; (5) Illegal Means; and (6) Avoidance of Illegal Ends.
Based on what we know now, the “Koh Criteria” seem to have been largely met in the case at hand.
Still, as Schmitt noted in 2013, a “legal right of humanitarian intervention is not widely accepted.” Citing various cases of such interventions, Schmitt said “it can be fairly argued that the right has crystallized into customary law over the past decades.” He conceded, however, that “[s]uch an argument is, of course, tenuous in light of apparent opposition to the doctrine by key States such as Russia and China; but it is not unreasonable.”
Schmitt did add what I think is an essential criterion for justifying humanitarian intervention: “[t]here must be some prospect of success, that is, the intervention must be likely to significantly alleviate the suffering to a degree not possible through non-forceful measures.” This too seems to have been met regarding yesterday’s missile strikes, notwithstanding a troubling detail.
According to McMaster, the chemical weapons themselves were not targeted out of concern that doing so could trigger the release of gas or harmful chemicals that could cause more injury than intended. This means that they could still exist for future use by Assad or seizure by terrorists. In my opinion, it is not unreasonable to conclude that the missile strikes, and the prospect of future attacks, could be enough to prompt Assad to give them up for good – thus meeting the “some prospect of success” standard Schmitt enunciates.
As is to be expected, some scholars are already insisting the attack was illegal under international (and U.S.) law, and there are bound to be more. But it appears that many nations, including key democracies, support the U.S.’s action. This is important because some experts believe that to be legally credible, humanitarian interventions ought to have multinational agreement beforehand and international participation in the operation.
I don’t think it is necessary to have formal agreement beforehand, or multinational participation in the operation, but an intervention should rarely be conducted if it is anticipated that it will meet with widespread global disapproval. On balance, I find the international reaction to these particular strikes to be sufficiently positive to further enhance their propriety.
So my sense is that we are seeing something of a new, albeit quite limited international norm emerging. It clearly is not one that would provide a carte blanche for military intervention. In fact, at this point I would not see it extending much further than the very particular circumstance of chemical (and biological) weapons.
The international opprobrium for these weapons is distinctively aggressive, as they uniquely tap into a primordial revulsion. The Week magazine explained in 2013 that:
[Although other weapons can inflict terrible injuries], chemical weapons evoke a strong emotional response, perhaps because they can be invisible, and victims often suffer slow and agonizing deaths, convulsing and gasping for breath. “This ‘chemical weapons taboo’ appears to have originated in the innate human aversion to poisonous substances.”
The missile strike can also help to revive respect for international norms that has been fading of late, mainly because there are too many actors who, like Assad, flout the law with no consequences to follow. If a tin-pot dictator in a third-rate country can defy a carefully orchestrated global agreement like the 2013 one that was expected to strip Syria of chemical weapons, isn’t the whole edifice of international law in peril of collapse? Can law that isn’t enforced really be respected?
It’s not surprising that a growing number of observers have been questioning the efficacy of international law. In a New Yorker essay last August (“Does Anyone in Syria Fear International Law?”) journalist Ben Taub lamented that “[n]owhere has the supposed deterrent of eventual justice proved so visibly ineffective as in Syria.” He made this incisive observation:
The Syrian war has become a conflict in which war crimes carry no consequences—present or, seemingly, future—and in which their perpetration has been normalized as a part of military strategy, rather than being seen as an aberration. The prevailing climate of impunity has emboldened other governments to carry out atrocities in the pursuit of their objectives…Western countries and the United Nations have spent the past five and a half years condemning atrocity after atrocity in Syria, to no avail.
In short, overly-blinkered analyses of the law governing the use of force that leave the international community impotent in the face of the kind of horror Syria inflicted in the recent chemical attack defeat the purpose for which the law exists in the first place.
We have to rebuild respect for international law and, unfortunately, that can require force like we saw yesterday. Absent consequences, international law could continue to devolve into irrelevance; indeed, interpretations of international law that don’t provide a viable avenue for accountability for the most egregious violations will doom it. Should we not say, to paraphrase Justice Jackson, that international law is not a suicide pact?
For sure, we need to be wary of the proverbial “slippery slope” and insist that actions like yesterday’s strike be very much the exception, but we also need to decisively demonstrate that there are real consequences for breaching as fundamental of an international prohibition as that against the use of chemical weapons. The missile strikes did just that.
In my view, the missile strikes met the requirements of international law on a number of grounds. Given the chaos in Syria, the unpredictability of the Assad regime, and the physical presence of hundreds of U.S. troops in Syria – as well as the risk of “normalizing the use of chemical weapons” which was enunciated by Secretary Tillerson – there appears to be an adequate factual justification for invoking the doctrine of anticipatory self-defense.
I also believe that in this instance the doctrine of humanitarian intervention provides a separate but limited legal basis because of the unusual circumstances of an atrocity involving an especially loathed weapon and a nation with a unique legal history with respect to that weapon.
U.S. authorities seem to understand the limits here. News reports say that U.S. officials described “the strike was a “one-off” intended to deter future chemical weapons attacks, and not an expansion of the U.S. role in the Syria war.” That makes sense to me, and I believe these statements signal that there would not be an expansion of the humanitarian intervention doctrine beyond the specific circumstances of weapons of mass destruction as was the case here. These strikes won’t end all the horror in Syria or anywhere else, but it is a step in the right direction.
But as we like to say at Lawfire, check the facts and the law, and decide for yourself!