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Traditionally, the evolution of customary international law was understood as a gradual process: in some idealized model, we might see first a few states, and then a few more, implicitly agreeing to follow a practice, and then we would gradually begin to see additional states doing the same thing. We would also gradually accumulate evidence that these various states are acting in such a way because they consider themselves legally bound to do so. Then, over time, we’ll see more and more states following suit both in word and deed, until at some point we can say with a great deal of confidence that such and such has evolved into a binding norm of customary international law.

That’s the idealized process through which norms of customary international law develop. In real life, of course, it’s rarely so neat and tidy. In fact, much of the time, the evolution of customary international law looks less like a gradual, trouble-free emergence of consensus than a continual process of contestation—a continual process of resistance and conflict between states, if you will. By “conflict” the author doesn’t necessarily mean armed force, but rather diplomatic conflict of all sorts: dueling demarches, dueling public statements, and so on.

Norms relating to humanitarian intervention offer a typical example. We are in a period in which we are seeing a norm struggling to emerge, if you will, but that process is not a smooth one, has not been a smooth one, and is unlikely to be a smooth one in the future. Indeed, when we think about norms related to humanitarian intervention or the Responsibility to Protect, if anything what we have seen has been a process of reaction, counter-reaction, counter-counterreaction and counter-counter-counter-reaction. We are still going through that cycle.

Publication Citation

Md. J. Int'l L. (forthcoming)