It might, says Samuel T. Morison of the Department of Defense (you may remember him from DoJ’s Pardon Office). The abstract:
The Alien Tort Statute (ATS) provides a federal forum for aliens to seek tort damages for certain violations of customary international law, including war crimes. In Sosa, the Supreme Court admonished the lower courts to exercise caution when creating new causes of action under the ATS, but this is entirely a matter of respecting the separation of powers. If Congress enacts a statute that “occupies the field,” the Court observed, then a judge’s task is to faithfully enforce the norms delineated in the statute. To date, the Military Commissions Act (MCA) has been almost completely ignored in human rights litigation under the ATS, perhaps because it does not, in terms, provide for civil remedies. But this overlooks the fact that the MCA is not an ordinary domestic criminal statute with a long-arm provision. Instead, it purports to “occupy the field” of war crimes, at least for U.S. domestic purposes. Perhaps most importantly, the MCA penalizes terrorism, broadly construed, providing material support for terrorism and conspiracy as war crimes, when committed by private, non-state actors in the context of and associated with an armed conflict. If this is a valid exercise of Congress’s prescriptive authority to define and punish violations against the law of nations, it follows that such norms should be actionable in ATS litigation. Accordingly, if the constitutionality of the MCA is ultimately affirmed by the Supreme Court, the decision will come with a previously unacknowledged systemic cost, namely a sharp increase in the scope of ATS liability.
Just in case you were wondering, this shows that the law of unintended consequences is alive and well.