International Law: What is it?

Because I teach a two-semester course in Western civilization that starts with prehistory and comes up to the present, I'm trying to increase my understanding of international relations by reading more on political theory. Currently, I'm slogging through Joseph S. Nye's Understanding International Conflicts: An Introduction to Theory and History.

Nye is that "soft power" guy that you've heard of.

I'm reading the fourth edition, but I see that a fifth edition is already in print. I presume that they do not differ much, but more recent is usually better if you're interested in seeing how political analysis is applied to contemporary cases. I'd be interested in reading how Nye analyzes the recent Iraq War in terms of its legitimacy based on international law. One of the charges against the American invasion has been that it was "illegal."

I have generally assumed that "illegal" here implies "against international law." But what does this mean? Don't misunderstand me -- I'm earnest about this question. What is international law?

Nye first tells me what it is not:

If we imagine the U.N. General Assembly as the equivalent of Congress, it is a very strange kind of legislature. It is based on the principle of one state, one vote, but that is not a principle that reflects either democracy or power relations in the world. Democracy rests on the principle of one person, one vote. In the U.N. General Assembly, the Maldive Islands with 100,000 people in the southern Indian Ocean has one vote and China, which is a country with over a billion people, has one vote. That means that a Maldive Islander has 10,000 times the voting power of a Chinese in the U.N. General Assembly, which does not fit well with the democratic criteria for legislatures. Nor is it a very good reflection of power, because the Maldive Islands has the same vote in the General Assembly as the United States or India or China. So there is an oddity about the General Assembly that makes states unwilling to have it pass binding legislation. U.N. General Assembly resolutions are just that: resolutions, not laws. (162)

Interesting. This means that in ignoring a U.N. resolution, a state breaks no laws. This doesn't mean that there are no consequences, but merely that the issue is not of a legal nature.

There is, of course, an international judiciary, the International Court of Justice, which Nye identifies as responsible for adjudicating claims based on international law:

[T]he International Court of Justice . . . consists of 15 judges elected for 9-year terms by the United Nations, but the International Court of Justice is not a world supreme court. States may refuse its jurisdiction, and a state may refuse to accept its judgments, even if the state has accepted the court's jurisdiction. (162)

So even if the International Court of Justice ruled that some state's act is 'illegal,' the ruling would not be binding upon that state unless that state agreed to make the ruling binding -- a rather unlikely scenario.

Moreover, courts don't make law; they interpret it. So . . . where does it come from? Nye locates the source of international law in the customs and agreements that regulate relations among states:

Public international law . . . consists of treaties, which are agreements among states, and customs, which are the generally accepted practices of states. (163)

Note that this sort of law lies outside the United Nations and depends upon the power of states for enforcement. One could try to appeal to the International Court of Justice to adjudicate a claim that another state has broken a treaty, but this returns us to the problem already noted, i.e., that the International Court's rulings are not binding.

So . . . is 'international law' really law?