Supreme Court international law has become a flashpoint in debates over whether the United States still shows a “decent respect to the opinions of mankind,” a principle evoked during the 250th anniversary of the Declaration of Independence. According to legal analysis, recent decisions reveal growing distance from global norms on treaties, customary rules and how international commitments shape U.S. statutes.
Supreme Court international law and treaties
One notable series of cases involved the Vienna Convention on Consular Relations, which guarantees foreign nationals detained in the United States the right to contact their home-country consulates. After the Court initially concluded that detainees could waive claims tied to a failure to inform them of that right, the International Court of Justice reached the opposite conclusion.
When similar cases returned to the Court, the majority said ICJ judgments merited “respectful consideration,” then declined to follow them. As a result, the United States remains the only one among 182 parties to the treaty to reject the ICJ’s interpretation.
Earlier decisions reflected the same posture. In one case, the Court parted from the widespread view that an extradition treaty does not allow a country to bypass formal proceedings by abducting a suspect from another state’s territory.
In another, it adopted a reading of the 1967 Refugee Convention that permitted turning back boats of Haitians on the high seas rather than at U.S. borders. In a separate matter, the Court interpreted a bilateral investment treaty using domestic contract principles instead of internationally accepted treaty-interpretation rules.
Customary international law under strain
The Court has shown similar skepticism toward customary international law, or CIL, which binds states where near-universal practice and acceptance establish obligations, absent a persistent objector. Even without a treaty, such norms bar refoulement, the return of refugees to states where they face a well-founded risk of persecution based on race, nationality, gender or similar grounds.
In the 2017 decision Jesner v. Arab Bank, PLC, the Court held that corporations could not be sued under the Alien Tort Statute for facilitating violations of CIL, including through terrorism. Observers noted the ruling did not reflect any broad international bar on corporate liability and ignored a growing trend to hold companies accountable for aiding arbitrary detention, forced labor and extrajudicial killings.
Statutes and the Charming Betsy canon
Chief Justice John Marshall’s 1804 instruction in Murray v. Schooner Charming Betsy advises that federal statutes should not be read to violate international law if another plausible construction exists. Critics say the modern Court has often sidestepped that canon.
In Mullin v. Al Otro Lado, the Court read the Immigration and Nationality Act to bar asylum claims by people who had not yet “arrived in” the United States. In Mullin v. Doe, it found that the Temporary Protected Status statute did not permit courts to review the Trump administration’s decision that Haitians and Syrians could be safely returned, reversing the prior administration’s view.
Neither ruling relied on Charming Betsy, and both increase the likelihood of refoulement, which is prohibited by the Refugee Convention and by CIL. In Learning Resources, Inc. v. Trump, the Court correctly concluded that the International Emergency Economic Powers Act did not authorize “Liberation Day” tariffs, although the reasoning did not highlight potential conflicts with U.S. obligations at the World Trade Organization.
When the Court aligned with global norms
There are examples of closer alignment. In Hamdan v. Rumsfeld, a narrow majority invoked Common Article 3 of the Geneva Conventions, which guarantees basic protections, including trial by a regularly constituted court, in conflicts “not of an international character.”
The administration had argued that foreign training and participation made the conflict international and outside those protections. The Court rejected that view, holding that the phrase is a term of art covering conflicts between a state and a non-state actor, such as al-Qaida.
Founding-era practice and later shifts
Historically, the Constitution presumed treaties to be self-executing components of the “supreme Law of the Land,” a design choice influenced by failures under the Articles of Confederation. Early leaders treated CIL as binding as well.
President George Washington relied on it to enforce U.S. neutrality during the war between Britain and revolutionary France. Chief Justice Marshall applied it to curb executive actions during the quasi-war with France and the War of 1812, including invalidating seizures that exceeded congressional authorization or contravened the law of nations.
Respect for international law has ebbed over time, predating the current bench. The nation’s rise to superpower status, with frequent entanglements abroad, has encouraged the view that general rules do not always apply to the United States.
Domestically, that shift has tended to expand executive authority at the expense of Congress and the courts, which once used international law as a constraint. Analysts argue the trend has accelerated under the Court’s current composition.
A jurisprudence that reduces certain domestic checks on executive action and narrows statutory and constitutional protections appears to be mirrored in its approach to the international legal order. Those patterns are increasingly evident in cases touching on immigration and border enforcement, alongside lower-court disputes such as Arizona immigration law challenges.