International Law and the U.S. Common Law of Foreign Official Immunity

In Samantar v. Yousuf, 130 S. Ct. 2278 (2010), the U.S. Supreme Court unanimously held that the Foreign Sovereign Immunities Act does not apply to lawsuits brought against foreign government officials for alleged human rights abuses. The Court did not necessarily clear the way for future human rights litigation against such officials, however, cautioning that such suits "may still be barred by foreign sovereign immunity under the common law". At the same time, the Court provided only minimal guidance as to the content and scope of common law immunity. Especially striking was the Court’s omission of any mention of the immunity of foreign officials under customary international law ("CIL"). In this Article, we explain why, notwithstanding the Supreme Court’s inattention in Samantar to the international law backdrop of the case, CIL immunity principles are likely to be relevant to the development of the post-Samantar common law of immunity. In considering the relationship between CIL and common law immunity, the Article makes three contributions. First, it sets forth a case for CIL’s relevance that is not dependent on a single theoretical perspective regarding the domestic status of CIL. Second, it presents a balanced assessment of the rapidly evolving CIL landscape, noting in particular the erosion of immunity protections for human rights violations in criminal proceedings and the lack of a similar erosion - at least so far - in civil suits for damages. Third, by emphasizing institutional considerations rather than arguing for a particular outcome, it isolates and analyzes particular variables - such as the views of the Executive Branch and the policies embodied in domestic statutes - that will shape how CIL affects the common law of immunity after Samantar.