Obama’s Bizarre New Theory of Customary International Law

As readers of the blog no doubt know, Syria is is one of seven states that have not ratified the Chemical Weapons Convention (CWC). (The others are Angola, Egypt, Israel, Myanmar, North Korea, and South Sudan.) To consider Syria’s use of chemical weapons as a rationale for attacking the country, the USG obviously needs to assume that the use of such weapons is prohibited by customary international law. I have no doubt that they are; after all, the CWC has been ratified by 96% of the world’s states, and nearly all international scholars accept the idea that so-called “law-making” treaties like the CWC can generate custom. As Brownlie says in his Principles of International Law, “the number of parties, the explicit acceptance of rules of law, and, in some cases, the declaratory nature of the provisions produce a strong law-creating effect at least as great as the general practice considered sufficient to create a customary rule.”

The key is “the number of parties.” I have never seen a scholar suggest — much less an actual international court or tribunal — that whether a treaty gives rise to custom depends on the percentage of the world’s population that lives within the territorial confines of the parties to the treaty. Yet that is exactly what the Obama administration seems to be arguing. Here is what Obama said a few days ago to reporters in Sweden (emphasis mine):

“My credibility is not on the line. The international community’s credibility is on the line,” he said.

“America and Congress’s credibility is on the line, because we give lip-service to the notion that these international norms are important.”

Mr Obama, who has previously said the use of chemical weapons would cross a “red line”, told reporters it was not him who set this line but the world, “when governments representing 98% of the world’s population said the use of chemical weapons are abhorrent and passed a treaty forbidding their use even when countries are engaged in war”.

I thought Obama’s emphasis on population might have been an aberration, a slip of the tongue or a inartfully-written phrase. But Samantha Power said the same thing yesterday at the Center for American Progress (emphasis mine):

In arguing for limited military action in the wake of this mass casualty chemical weapons atrocity, we are not arguing that Syrian lives are worth protecting only when they are threatened with poison gas.

Rather, we are reaffirming what the world has already made plain in laying down its collective judgment on chemical weapons. There is something different about chemical warfare that raises the stakes for the United States and raises the stakes for the world.

There are many reasons the governments representing 98 percent of the world’s population, including all 15 members of the U.N. Security Council, agreed to ban chemical weapons. 

Is the Obama administration promoting a new theory of custom, one in which the customary status of  treaty depends upon the percentage of the world’s population represented by states that have ratified it, not the number of states themselves? It certainly seems to be. But why? Why not simply point out that the CWC has been ratified by 96% of states instead? Surely that must be enough to generate custom — perhaps even jus cogens!

May I venture a cynical answer? If the Obama administration had gone the black-letter route, arguing that Syria is bound by the CWC’s prohibition on the use of chemical weapons because 186 states have ratified the CWC, that would mean the US is bound as a matter of custom by a number of treaties that it has refused to ratify. The Convention on the Rights of the Child, for example, has been ratified by 190 states — 98%. So, too, the Biodiversity Convention. Even the much-maligned Kyoto Protocol has been ratified by 189 states, also 98%.

But now apply Obama’s new “98% of the world’s population” test for customary international law. Which treaties the US has refused to ratify reflect custom under that test? None of them — because the US represents 5% of the world’s population. Indeed, no treaty that does not include the US could ever cross the 98% threshold.

Magic! And convenient magic at that.

PS. I am not claiming it is 100% certain — or even 98%… — that Obama and Power are articulating a new view of the relationship between treaties and custom. It’s completely possible they are making nothing more than a political argument. But I assume that lawyers vet these speeches — especially given the surprisingly central role IL has played in the debate over Syria. I also assume that Obama and Power are aware that the CWC, which both have specifically invoked (not simply “norms” against the use of chemical weapons), does not directly bind Syria. So I think it’s fair to at least speculate that, in defending the supposed “red line” drawn by the CWC — itself illusory, as the CWC does not permit the use of force in response to breaches — it’s not an accident that neither Obama nor Power said “96% of the world’s states” but strangely emphasized 98% of the world’s population instead.