Presidents have long had an uneasy relationship with international law. If it is true that most states follow most international law most of the time, that probably goes for Presidents, too. Whether Presidents follow international law out of a belief that they, and the United States, must comply with it, or whether they follow international law because much of it simply describes general regularities in state conduct, remains a debated question. (1) Presidents, however, have stretched or violated international law at significant moments in American history where important national security and foreign policy goals were at stake. Recently, international law has served as a political rallying point against the anti-terrorism policies of the Bush administration regarding the use of force, detention, interrogation, and military trial.
Academic critics of the Bush administration make a broad argument: violations of international rules are not only illegal as a matter of international law, but also violate the Constitution. (2) Repeating claims made against the Reagan administration, these scholars assert that the Constitution includes international law in the Laws of the Land under Article VI of the Supremacy Clause. (3) According to this argument, Article II's requirement that the President enforce the law includes the enforcement of international law. "There can be little doubt," Professor Louis Henkin has argued, "that the President has the duty, as well as the authority, to take care that international law, as part of the law of the United States, is faithfully executed." (4) Altogether there are three possible forms of this view. (5) On one account, international law is binding on the President unless he is exercising a statutory authority; he has no independent constitutional authority to violate international law. In the second form, international law is binding on the President unless he is exercising his own constitutional authority; a delegation of power from Congress cannot authorize a violation of constitutional law. Third, some claim that the President cannot violate certain forms of international law regardless of his domestic authority. (6) One corollary of asserting that international law constitutes federal law under the Supremacy Clause is that federal courts should be able to enjoin the President from violating it in properly brought cases.
The academic criticism of presidential violations of international law is not descriptive of judicial practice, but instead is normative in design. The leading Supreme Court case on the point, The Paquete Habana, states that "[i]nternational law is part of our law," but that "the customs and usages of civilized nations" will be given effect only if "there is no treaty, and no controlling executive or legislative act or judicial decision" to the contrary. (7) While supporters of international law as a restraint on presidential power take comfort from the first part of The Paquete Habana's holding, the Court also clearly held that the President could override customary international law. (8) It appears that no federal court of appeals has ever held that customary international law limits presidential decisions. (9) The only district court to reach such a conclusion was affirmed, but the court of appeals did not address the customary international law holding. (10) Much attention has focused on the applicability of customary international law in domestic law through the Alien Tort Statute ("ATS"). The ATS is not directly relevant here, however, because it represents international law that has been incorporated by an explicit congressional act, rather than customary international law which limits the President by its own force. (11) So far, courts have found that sovereign immunity precludes ATS suits against the United States government and, presumably, the President. (12)
Surprisingly, little academic literature critically assesses the contention that the President is bound by customary international law. …