Customary International Law as U.S. Law: A Critique of the Revisionist and Intermediate Positions and a Defense of the Modern Position

INTRODUCTION I. THE MODERN POSITION" EXPLICATION AND PRELIMINARY DEFENSE A. The Basic Case for the Modern Position 1. Constitutional Structure and Original Intent 2. Pre-Erie Doctrine a. State Authority to Depart from Customary International Law b. Supreme Court Review of Customary International Law c. The General Law as an Intermediate Status 3. Post-Erie Doctrine B. The Limits of the Modern Position 1. Sabbatino and the Inapplicability of Some Customary International Law Norms to Some Acts of Foreign States 2. The Paquete Habana and the Applicability of Customary International Law to Federal Officials C. Sosa and the Modern Position II. THE INTERMEDIATE THEORIES A. Ramsey's Position 1. Nonpreemptive Federal Law as State Law 2. Ramsey's Textual and Historical Support B. Young's Position 1. Young's Criticisms of the Modern Position 2. Young's Intermediate Status for Customary International Law a. State Choice-of-Law Rules i. The Diversity and Indeterminacy of Existing Choice-of-Law Approaches ii. The Inappositeness of Choice-of-Law Rules iii. The Likelihood of Special Choice-of-Law Rules iv. The Role of the Federal Courts v. Summary b. Federal Choice-of-Law Rules C. Aleinikoff's Position D. The Bellia-Clark Position E. The Bradley-Goldsmith-Moore Position III. THE MODERN POSITION, REDUX A. The New Ways of Making Customary International Law B. The New Topics Addressed by Customary International Law IV. STATE INCORPORATION OF CUSTOMARY INTERNATIONAL LAW CONCLUSION INTRODUCTION In a recent referendum, the citizens of Oklahoma overwhelmingly approved a State constitutional amendment providing that the courts of the State "shall not consider international law or Sharia law" in rendering their decisions. (1) The amendment's exclusion of Sharia law has garnered most of the media attention, (2) but more consequential by far is the measure's directive to the State courts to disregard international law. Similar measures have been proposed in other States, some of them merely barring consideration of Sharia law or foreign law, (3) but others barring consideration of international law as well. (4) These measures are clearly unconstitutional insofar as they would prohibit the State courts from enforcing one of the two main forms of international law--treaties--as the U.S. Constitution by its terms requires State courts to give effect to the nation's treaties, "any Thing in the Constitution or Laws of any State to the Contrary notwithstanding." (5) But the federal Constitution does not expressly address the status of the other principal form of international law--customary international law, or the unwritten law that governs the relations among states and "results from a general and consistent practice of states followed by them from a sense of legal obligation." (6) These proposed State laws thus starkly raise the question whether the States may prohibit their courts from giving effect to the United States' obligations under customary international law. (7) The answer provided by the Restatement (Third) of Foreign Relations Law is a clear "no." Reflecting the settled view regarding the status of customary international law in the U.S. legal system at the time that it was approved in 1987, the Restatement asserts that such law has the status of federal law. (8) As such, it preempts inconsistent State law; State courts must follow federal court interpretations of it; and State court interpretations of it are reviewable in the federal courts. …