This Article provides a roadmap for cases involving foreign official immunity in U.S. courts. In 2010, the U.S. Supreme Court held in Samantar v. Yousuf that the Foreign Sovereign Immunities Act (FSIA) does not govern the immunity of foreign officials. Since Samantar, dozens of decisions have addressed questions of foreign official immunity. Yet, U.S. courts often seem lost. They frequently fail to engage with the customary international law rules of foreign official immunity, instead reaching back to an outdated provision of the 1965 Restatement (Second) of Foreign Relations Law. Courts are divided on how much deference to give the executive branch when it suggests immunity or nonimmunity in a particular case. They are even unsure of which procedural rules to apply. For example, courts continue to treat foreign official immunity as a question of subject matter jurisdiction, following a path worn by the FSIA, even though Samantar clearly held that the FSIA does not apply to natural persons.

This Article makes three distinct contributions. First, it provides a concise overview of the international law rules that govern foreign official immunity and explains why courts should resist the temptation to expand the federal common law of immunity beyond what international law clearly requires. Second, it contributes to the literature on deference to the executive in foreign affairs by examining the deference owed to executive suggestions of foreign official immunity or nonimmunity. Third, it addresses a series of critical procedural questions that have so far received no academic attention, arguing among other things that foreign official immunity should be treated not as a question of subject matter jurisdiction but rather as an affirmative defense.