My friend Tony Arend discusses the recent decision in Kiobel, which limits corporate liability under the Alien Tort Claims Act, bringing to bear his expertise as a leading international law expert:
The methodology the court uses for determining the existence of a rule of customary international law is consistent with what I believe to be the correct, positivist understanding of international law. (An approach that I have elaborated upon in more detail here.) In order for a rule of custom to exist there must be both state practice and a belief by states that the practice is obligatory, opinio juris. What the court avoids is assuming the existence of a rule of custom because it might seem logical for such rule to exist. In other words, the court will admit that a rule of custom exists if, and only if, it can demonstrate that state practice created such a rule. I think this is the correct method for evaluating the existence of a rule of custom.
[On the merits,] I find the arguments advanced by Judge Carbranes quite persuasive. That is, the court does seem to demonstrate that states have not created a specific rule of custom establishing corporate liability.
