Does international law bind superpowers?

I continue to be amazed when educated people say that international law is not binding on the United States, or that international law cannot be enforced against a superpower, or that the United States can violate international law whenever it wants to, or that international law doesn’t exist.

Let’s take the strongest of these claims: the enforcement claim. Let’s stipulate that if international law cannot be enforced against a superpower, then it doesn’t exist.

Hans Kelsen, whose fundamental position was that law is nothing more nor less than a coercive system, argued in 1948 when he drew his attention to international law that coercion in international law takes the form of forcible reprisals. A state commits a delict (in Kelsen’s useful terminology) when it violates a rule of international law. The state that commits a delict opens itself up to a reprisal by other states. A reprisal is a kind of countermeasure, a tit-for-tat retaliation. The most important characteristic of a reprisal is that it would be a delict if standing alone. What saves it from being delict is that it may permissibly be taken, under customary international law, in retaliation for a delict.

Kelsen came to the conclusion that international law is a coercive order because it is enforced through the reprisal mechanism. I think I will have no difficulty in persuading you, at least, that this is exactly what happens under a treaty.

Suppose nation A decides to violate Article 13 of a treaty it has entered into with states B, C, and D. Under the general customary rule of reciprocity, A’s violation of Article 13 immediately releases B, C, and D from observance of Article 13 in their dealings with A. Of course, A already took this into account when it decided to violate Article 13. A went ahead with the violation because it calculated that its benefit in violating Article 13 exceeded the cost of releasing B, C, and D from their corresponding obligations of Article 13.

But treaties are “package deals.” State B, for example, might have signed on to the treaty because Article 13 was especially beneficial to itself even though Article 8 was costly even though it was especially beneficial to A. All four nations were able to agree on the final treaty language because there were goodies in the treaty package for all of them.

So now A comes along and decides to abrogate Article 13. We have just postulated that B is the leading beneficiary of Article 13 and would not have signed the treaty if Article 13 had been omitted. Therefore, if B’s remedy for A’s breach were confined to the reciprocal remedy—that is, the release of B from Article 13—that would not be good enough. Article 13 was never onerous to B in the first place, it was only onerous to A.

Enter the customary international law of treaties. Thousands of years ago, and well before the Vienna Convention on the Law of Treaties, the customary international rule developed that allowed a treaty party to retaliate for a breach by disavowing a different provision in the same treaty (in the earliest law, a breach permitted the other party or parties to withdraw completely from the treaty).

This is the quintessential case of a Kelsenian retaliation. In an article spelling all this out, I called it a “tit-for-a-different-tat.” Of course, the reprisal has to be proportionate to the initial delict; if the reprisal went too far, it would itself constitute a new delict. I considered the problem of runaway retaliation in the article.

Now there is only one analytical step left: we go from treaty law to customary law as a whole. Consider all of international law as a huge interconnected system, very much like a huge treaty with every nation as party. A delict by one state invites a reprisal from another state (usually the injured state). In this theoretical model, all the rules of international law are enforceable by tit-for-a-different-tat reprisals.

Suddenly we should see how easy it is to enforce international rules against the United States. There are thousands, perhaps millions, of rules of customary international law, and additional thousands or hundreds of thousands of rules in treaties we have ratified. All these rules give legal entitlements to the United States in millions of areas and circumstances, just as they also give rise to obligations of obedience. The result is that most of the time we do not break rules of international law because of fear of retaliation. As Louis Henkin famously said, “Almost all nations observe almost all principles of international law and almost all of their obligations almost all of the time.”

OK, you want me to be specific. Exactly where and how is the United States vulnerable to forcible reprisals? Certainly by nothing so crude or futile as other countries’ dropping bombs upon the territory of the United States, even though this is the first thing that people think of.

The assets and values of the United States are not confined to its territory. The United States is vulnerable because of its investments and nationals located all over the world. The United States has major financial investments in foreign-owned companies in nearly every state. More importantly, at any given time there are hundreds of thousands of American citizens either traveling or residing abroad. The Census Bureau reports that in 1998 there were over 56,000 Americans traveling abroad (compared to 46,000 foreign tourists visiting the United States). Even more striking are the figures of American citizens residing abroad as reported by the Bureau of Consular Affairs in 1999. There were 27,600 citizens residing in Buenos Aires, 55,500 in Sydney, 250,000 in Toronto, 48,220 in Hong Kong, 75,000 in Paris, 138,815 in Frankfurt, 45,000 in Tokyo, and 441,680 in Mexico City. Among the smaller countries which could become “hot spots,” the Bureau reports 646 American citizens living in Albania, 1,320 in Bangladesh, 1,600 in Bosnia, 440 in Congo, 2,000 in Cuba, 10,000 in El Salvador, 546 in Gambia, 11,000 in Haiti, 18,000 in Israel (Tel Aviv), 8,000 in Jordan, and 6,639 in Kuala Lumpur, and I’ve taken those examples from just the first half of the list. To these figures must be added the many thousands of American military personnel and their dependents on foreign bases.

How many American nationals must a country threaten to make the United States take notice? Just 50 were sufficient in 1978 when Iran arrested that number of American diplomatic and consular personnel in Tehran. The hostage-taking led to severe repercussions in the United States including perhaps the defeat of presidential incumbent Jimmy Carter in the election of 1980. Of course, the World Court ruled specifically that the Iranian hostage-taking was not a reprisal for anything the United States had done. The result, as I spelled out in the article previously mentioned, was that the United States went ahead with its own reprisal against Iran, one that was completely successful in getting all the hostages back unharmed.

Superpower vulnerability is enhanced by the bluntness of the military instrument. For example, even though the United States could have annihilated Iran with a volley of nuclear ICBMs, such a wholly disproportionate retaliation would not have saved the hostages. The global scatter of assets and persons from all nations has virtually assured the universal efficacy of the international reprisal system. Indeed, in a shrinking world, the reprisal system is likely to become increasingly efficient. Perhaps there is a correspondence between the efficacy of peaceable reprisals and the recent findings that there has been a steady decline in the global magnitude of armed conflict following its peak in the early 1990s.