Noah Millman makes an excellent point about Syria and enforcing international norms:

You can’t enforce an “international norm” on your own recognizances. There has to be some kind of internationally recognized process, and some kind of authorization. That is what puts the “collective” in collective security. Since the creation of the United Nations, the only legitimate justification for the unilateral use of force is self-defense. Nobody alleges that a strike against Syria is an act in self-defense.

That’s right, which is why what strikes the U.S. and its allies launch against Syrian forces in the next few days will be contrary to international law. Now most Americans and even some American liberal internationalists probably don’t care about this, but it is a fairly significant flaw in the claim that the forthcoming missile strikes have something to do with enforcing international norms and creating a “rules-based order.” Indeed, it sinks the only argument for this particular attack.

Millman goes on to say that “an attack would be an open declaration that the United States arrogates to itself the right to determine what the law is, who has violated it, what punishment they deserve, and to take whatever action is necessary to see it carried out.” He doesn’t think this is compatible with liberal internationalism, and maybe he’s right about that. Unfortunately, it is very compatible with the way that the U.S. has treated international law when it comes to matters of proliferation and violations of other states’ sovereignty. International law matters greatly to Washington when it is a bludgeon to be used against other states, and it seems that it is something to be ignored more or less completely when it is an obstacle to bludgeoning other states.