Justice Gray famously wrote in The Paquete Habana1 that "[iInternational law is part of our law, and must be ascertained and administered by the courts of justice of appropriate jurisdiction as often as questions of right depending upon it are duly presented for their determination."2 The succeeding century has seen a great deal of sparring among courts and commentators as to what, exactly, that memorable phrase means for the status of international law within the domestic legal system. The Paquete Habana itself concerned customary international law, and scholars continue to debate whether that law amounts to supreme federal law.3 More recently, controversy has shifted to the domestic status of treaties.4 The Supremacy Clause plainly makes treaties "part of our law";5 the question is what that status entails for the interpretation and enforcement of treaty provisions.
The interpretation and force of treaties in domestic courts lie at the heart of a line of recent cases concerning the Vienna Convention on Consular Relations (VCCR).6 The VCCR requires law enforcement officials to notify foreign nationals whom they arrest of the foreign nationals' right to consult with their consulates.7 Dual opinions by the International Court of Justice (ICJ), culminating in its 2004 Avena9, decision, found the United States in violation of the VCCR and required American courts to give the treaty effect, notwithstanding domestic doctrines limiting the enforceability of its provisions in certain circumstances.9 The U.S. Supreme Court rejected Avena's construction of the treaty in Sanchez-Llamas v. Oregon,10 refusing to give much deference to the ICJ' s interpretation."
The VCCR saga took a more curious turn when, in a rare fit of multilateralism, President George W. Bush sought to enforce the ICJ' s judgment by directing an unusual executive order to the state courts.12 The Supreme Court rejected the President's effort in Medellin v. Texas,13 and it further held that ICJ judgments lack "self-executing" effect within the domestic legal system.14 Medellin's latter holding was the first Supreme Court intervention in recent memory into a longstanding debate among the courts of appeals (and scholars of foreign relations law) concerning when a treaty should be considered to have domestic legal force without further action by the national political branches.
This extraordinary sequence of rulings and events concerning the VCCR may well be sui generis in any number of ways, but the issues of interpretive deference and self-execution that it raises are likely to recur across any number of other treaty regimes, from trade to terrorism. In debates about the domestic status of international law generally, internationalists typically invoke The Paquete Habana for the proposition that domestic courts and officials should be more receptive to international law;15 nationalists, on the other hand, generally seek to maintain a firewall between international and domestic law, and to leave decisions about which norms pass through that firewall to national political officials.16 I argue here that, contrary to conventional assumptions, The Paquete Habana principle does not necessarily support various internationalist doctrinal prescriptions and that, properly considered, it frequently buttresses more nationalist positions.
The point is a general one. In an earlier piece on customary international law (CIL), I argued that the "modern position" - which treats CIL norms as supreme federal law with binding effect in every case within the scope of those norms - is not actually consistent with the way federal common law works.17 Rather, federal courts articulate federal common law rules only when the otherwise-applicable state law would conflict with some particular federal interest (and not some generic federal interest in "uniformity" for its own sake).18 Treating CIL as part of our law would thus subject it to the same highly contextual conflicts analysis that federal courts apply in domestic cases not governed by federal statutes, treaties, or constitutional provisions. …