Over at Opinio Juris, prominent international law scholar Peter Spiro criticizes Eugene Volokh's and (by implication) my claim that U.S. should try to block the overriding of domestic law by international law norms. He argues that such resistance is futile, and that we should instead work to improve the substantive content of international law norms themselves:

I think this is a lost cause over the long run, which is to say nothing about the merits of hate-speech bans or any other particular international norm. There are too many ways in which international law now insinuates itself to mount this sort of centralized defense. For instance, if the states start to pick up on an international norm, it will eventually be indigenized, making its way upwards to the organs of the national government (think what's happening now with Kyoto). Ditto for non-state actors (think universities and hate-speech codes). I think the Supreme Court is likely to desist from the open use of IL sources for the moment, in the face of the push-back after Roper, but that won't stop justices from incorporating IL norms under cover. Over the long run resistance will be futile.

Which all might be by way of a call to arms of a different sort: to try to influence international norms at the international level, rather than wasting time trying to shut them at the border. The US is obviously a powerful actor in the making of international law. It won't win every battle (and this particular one may be a loss) but over the long run that will present the better strategy for protecting (and projecting) our conception of constitutional liberties.

I think that Spiro's conclusion is, at the very least, overdrawn. At most, he shows that we cannot stop all overriding of domestic law by international law. That doesn't mean that we can't stop at least some of it, perhaps even succeed in the vast majority of cases. Over the last several decades, the US has successfully resisted the domestic imposition of numerous international law norms, including "hate speech" laws, the 1977 Protocols to the Geneva Convention [which I originally mislabeled as the "Third Protocol"], the New World Information Order (mentioned in my last post), the Law of the Sea Treaty (which was eventually revamped as a result of US objections and the Reagan Administration's refusal to sign and follow the original version) and others.

Furthermore, Spiro's examples conflate two very different modes of incorporation of international law into domestic law: what John McGinnis and I call "raw international law" and the domestic incorporation of international law through ordinary domestic legislative processes. Raw international law consists of international law norms (e.g. - customary international law) that we have not ratified through congressional or state legislation or through the treaty ratification process. It is this kind of international law that McGinnis and I argue is likely to be systematically inferior to domestic law. By contrast, international law that has passed through the domestic lawmaking process is likely to be no worse, on average, than other domestic legislation. It is only the domestic incorporation of raw international law that should be categorically rejected. There is as yet no reason to believe that we can't resist successfully, and indeed we have done so on numerous past occasions.

Finally, I agree with Spiro that we should use our leverage to improve the substance of international law norms. Indeed, in my last post I suggested one possible strategy for doing so: denying funding to the UN Human Rights Council and other international organizations that promote international law norms that violate civil liberties.

However, the two strategies are not mutually exclusive. The United States should work to improve the content of international law, while simultaneously doing all we can to prevent the overriding of domestic law by harmful international law norms that may be enacted by others over our opposition. The two strategies may even be mutually reinforcing: international organizations and foreign powers may be less likely to try to create harmful new international law norms if they know that the US will refuse to follow them. Our chances of succeeding in both endeavors will, of course, increase if other liberal democracies adopt similar policies.

UPDATE: Peter Spiro briefly replies to this post here. He writes:

I want sometime soon to set out more detailed thoughts on the piece he's co-authored with John McGuinness on the incorporation of international law. For the moment, I'd just say that unlike Ilya and John I would take account of the many non-formal (or at least non-federal) channels through which IL is making itself felt in the US. Just because it's not working its way through the federal government doesn't make it illegitimate. Is there a process problem with California adopting Kyoto's standards? With a university adopting international standards on hate speech (again, leaving the merits aside)? My point is that this is where the action is. Formal incorporation (political or judicial) comes in the way of a mopping-up exercise or as an afterthought, after the real battles have been fought in the trenches.

Just to clarify, John McGinnis and I have no process objection to state legislatures incorporating international law norms into statutes, except in cases where doing so violates the US Constitution; such legislation is, on average, likely to be no worse than other state legislation. Our critique is directed at the claim that raw international law should override domestic law even in cases where no domestic legislation has been passed incorporating it and (as Professor Spiro has argued) even where the international law in question violates the US Constitution. Also, I do not agree that "formal incorporation" is just a "mopping-up exercise or . . . an afterthought." Passing legislation is costly and difficult and requires the support of key political actors and (often) of the general public. Ratifying a treaty or passing a constitutional amendment requires even broader support. Raw international law, by contrast, is often created with the support of only a coalition of relatively unaccountable international elites and authoritarian rulers of foreign states.