In the New York Times yesterday, Northwestern University political scientist Ian Hurd lays down the law on Syria and intervention:

As a legal matter, the Syrian government’s use of chemical weapons does not automatically justify armed intervention by the United States… Syria is a party to neither the Biological Weapons Convention of 1972 nor the Chemical Weapons Convention of 1993… Syria is a party to the Geneva Protocol, a 1925 treaty that bans the use of toxic gases in wars. But this treaty was designed after World War I with international war in mind, not internal conflicts.

[And] the conventions also don’t mean much unless the Security Council agrees to act. The United Nations Charter… demands that states refrain “from the threat or use of force against the territorial integrity or political independence of any state.” The use of force is permitted when authorized by the Security Council or for self-defense  — but not purely on humanitarian grounds.

Of course ethics, not only laws, should guide policy decisions…  if the White House takes international law seriously — as the State Department does — it cannot try to have it both ways. It must either argue that an “illegal but legitimate” intervention is better than doing nothing, or assert that international law has changed — strategies that I call “constructive noncompliance.” In the case of Syria, I vote for the latter.

Hurd is right about a great many things: that Syria’s obligations under treaty law are weaker than people want to think; that there are legal tensions here that the US cannot and shouldn’t try to wish away; and that a decision must be made between doing something and doing something lawfully; and that the robustness of international norms around both R2P and chemical weapons are at stake in how the US and UK frame the discussion.

But I think Hurd is both under-stating the case about Syria’s international legal obligations, and over-stating the case about US options in framing a potential military intervention. International law indeed is “changing” – but the relevant changes he describes apply to Syria’s responsibility to its civilians, not to the US’ right to reinterpret the UN Charter. And ultimately, as he points out, even Syria’s violations of law don’t make it lawful for the US to intervene without a Security Council resolution – however ethically right such an intervention may be. The two are really separate legal questions so I’ll address them separately below.

First: did Syria’s use of chemical weapons put it in violation of international law? I should begin by pointing out that Syria is still only suspected of having used these weapons, and the UN investigation into the source of the attack is still ongoing. However, let’s assume for the sake of argument that the attack came from the Syrian government and not from insurgents aiming to provoke a Western intervention. As a “legal matter,” Hurd is right to point out that Syria is not technically in violation of the Chemical Weapons Convention (CWC) or the Rome Statute of the ICC (which also codifies the chemical weapons taboo), being a non-signatory to both treaties, as states are only bound by treaty obligations they agree to. Syria is, however, in violation of the International Covenant on Civil and Political Rights and Common Article 3 of the Geneva Conventions which outlaws arbitrary killing of one’s citizens  in peacetime or of noncombatants – even in civil wars. Moreover, despite not being bound by current treaty law on chemical weapons, Syria is arguably in violation of the international customary law prohibiting their use. The CWC is so widely ratified, the prohibition on use so frequently cited in war crimes jurisprudence, the behavior of most states so consistently in compliance that this “norm” is in fact considered by the International Committee of the Red Cross to have the status of customary law. Indeed, the fact that Syria is bending over backward to deny its use of the weapons strongly suggests that it too considers itself beholden to these rules.

But as Hurd secondly points out, none of this really matters to the question of the legality of a US strike against Syria, since military strikes against other states are governed by a completely different set of rules: the UN Charter which in almost ll circustances renders dispute resolution by force unlawful (Article 2). Except in cases of self-defense (Article 51), only the Security Council can legalize the use of armed force (Chapter 7), so I see only three ways at best in which a strike against Syria for internal, humanitarian reasons could be considered “legal.” First would be the highly unlikely event that both China and Russia could be persuaded to abstain from a veto in the Security Council. Second would be a Uniting for Peace Resolution in the General Assembly – also unlikely and arguably a weaker legal position given the non-binding authority of the GA. Third, states subject to significant refugee flows as a result of the crisis could undertake an intervention on the basis of “self-defense.” Note that this argument would be agnostic in terms of chemical weapons per se so it would be a very different kind of intervention; and it implies that Turkey or Jordan would take the lead, not NATO [as an organization or other Western] powers. By contrast, if Western powers led the attack without the Security Council or the General Assembly, it is hard to argue that it would be legal – regardless of what Syria has done inside its borders.

That said, there are a number of reasons to think an intervention might be considered normatively legitimate in empirical terms, despite its technical illegality. There is the precedent of Kosovo, where NATO failed to seek a UN resolution but where Russia also failed to pass a resolution condemning the air war – a sign Nicholas Wheeler has argued demonstrates the existence of a humanitarian intervention norm despite its absence in law. There is the Responsibility to Protect (R2P) doctrine, affirmed in numerous soft law instruments and in the behavior and rhetoric of the Libya intervention. There is the inter-subjective horror of chemical warfare shared by international society and the sense that this is a crime not just against individual human beings but against all humanity. Whether or not a majority of the global community would react to affirm the use of military strikes even without a Security Council authorization to enforce this taboo is something we can only know in hindsight. However the refusal of the Security Council to condemn NATO’s illegal air war in Kosovo because it was widely seen as an enforcement of the anti-genocide taboo suggests this could be the case. In each of these cases, however, it would not change the fact that the war itself would be a violation of the UN Charter. It is only an question of whether international normative sentiment would be sufficient to trump international law.

That’s an empirical question. The important policy question is whether it suits US interests to affirm international law, or to trump it on ethical grounds when warranted. I agree with Hurd’s claim that the US can’t easily find legal cover for a strike. But of the remaining two options – admit this is an ethically appropriate but unlawful strike, or claim the “law has changed” – I don’t agree with Hurd that the latter is the right course of action. The law on chemical weapons may have changed to the point that it supercedes the absence of Syrian treaty obligations; but R2P remains an incipient norm, not a law, and remains in tension with codified UN Charter law which binds the US. Trying to pretend otherwise will only undermine US moral authority, and sounds too much like other creative re-interpretations of international law by the US in recent years around torture, extrajudicial execution, and detainee status.

If the goal is to affirm international norms, the far better way to frame a potential military strike is in terms of ethics and norms, not law. The US could argue (I’m not saying I agree) that the chemical weapons norm is so strong and so vital to global security interests that enforcing it justifies the unlawful use of force. I am not saying that this is the right policy – in a future post I will analyze more clearly why the US might consider other options for “norm enforcement and affirmation” before jumping to military strikes if the goal is to enforce the chemical weapons norm rather than to protect civilians per se. But I will say that, as Hurd points out, the US can’t have its cake and eat it too on this legal question.