It is worth emphasizing why I think the "choice of law" question is so crucial to resolving this case (and why Justice Breyer agrees with me on this point). In its 2004 decision, Sosa v. Alvarez-Machain, the Supreme Court decided that the Alien Tort Statute authorized the recognition of causes of action that were "specific, universal, and obligatory." In that case, the Court actually rejected the norm of "arbitrary detention" as insufficiently universal as applied to the facts of that case.
The idea behind the Sosa standard, the Court emphasized, is that federal courts should only be allowing lawsuits over norms that are uncontroversial and which other countries would not dispute. Reaching out and creating "disputable" causes of action overstepped the narrow mandate the federal courts have under the Alien Tort Statute, and raised the potential of federal courts causing conflicts with the President and Congress on the one hand, or with foreign countries on the other.
This baseline standard is important to keep in mind when evaluating Professor Weissbrodt's arguments in favor of a general international law duty for business corporations. Althought Professor Weissbrodt marshals some interesting precedents, I seriously doubt they would satisfy Sosa's "specific, universal, and obligatory" standard.
For instance, the Convention Against Genocide itself, which Professor Weissbrodt cites, reflects ambiguities as to whether it applies to corporations. Article IV, for instance, states:
Persons committing genocide or any of the other acts enumerated in article III shall be punished, whether they are constitutionally responsible rulers, public officials or private individuals.
(Emphasis added). As you can see, the language Professor Weissbrodt quotes does not apply generally under the Convention and, in fact, this language illustrates that the Convention does not impose any duties directly on corporations that are "specific, universal, and obligatory." The phrase "private individuals" generally refers to natural persons.
Moreover, the history of the drafting of the Rome Statute of the International Criminal Court and the trials of Nazis after World War II reflect hesitation about imposing duties directly on corporations. The drafters of the Rome Statute debated, and then decided not to adopt a civil remedy and, further, not to bring corporations within its jurisdiction. The victorious WWII powers considered, but ultimately did not bring any corporations to trial (although the owners or officers of the corporations were prosecuted). It is therefore not surprising that countries such as the UK and the Netherlands have filed amicus briefs in this case arguing that there is no general norm imposing duties on corporations under international law.
I do not doubt that corporations could, via a formal act of lawmaking such as an amendment to the Alien Tort Statute or formal treaty, acquire duties for violating certain international law obligations. This would be a deliberate decision by the Congress or the President and Senate to take a side in the development of international law norms. But that decision, which is fraught with complicated policy considerations, should be left to the Congress or the President and Senate. It should not be left wholly within the discretion of federal courts acting pursuant to a deeply ambiguous statutory mandate.
I want to thank Point of Law again for hosting this great discussion, and to Professor Weissbrodt for his participation.