The Supreme Court held that the Vienna Convention on Consular Relations permits foreign detainees to waive the right to consult their home country’s consulate if the issue is not raised at trial or on direct appeal. The International Court of Justice disagreed with the Supreme Court's interpretation that the Vienna Convention on Consular Relations permits waiver of consular access rights. The Vienna Convention on Consular Relations is a treaty to which the United States is a party and took the lead in drafting. There are 182 state parties to the Vienna Convention on Consular Relations.

This ruling aligns with a broader pattern of the Supreme Court departing from international legal consensus in its interpretations of treaties and customary law. The Supreme Court departed from an international consensus by ruling that an extradition treaty does not prohibit a state from kidnapping a suspect in another nation's territory to evade extradition proceedings. The Supreme Court adopted an interpretation of the 1967 Refugee Convention that allowed for turning back boats carrying persons fleeing Haiti on the high seas rather than in U.S. waters. The Supreme Court interpreted a bilateral investment treaty by applying domestic contract law principles rather than the distinctive principles used to interpret treaties internationally.

Customary international law arises when a near consensus of the world’s states recognizes a prohibition or a duty. Under customary international law, a resulting rule binds every government unless a particular state had earlier consistently objected to being bound. Customary international law obligates states not to return refugees to countries where they have a well-founded fear of persecution based on race, national origin, gender, or similar bases. In the 2017 case Jesner v. Arab Bank, PLC, the Supreme Court ruled that a private corporation cannot be sued for facilitating a state’s violations of customary international law through terrorism.

In Mullin v. Al Otro Lado, the Supreme Court read the Immigration and Nationality Act to preclude persons not yet having 'arrived in' the United States from seeking asylum under the statute. In Mullin v. Doe, the Supreme Court decided that the federal Temporary Protected Status statute did not permit judicial review of the Trump administration’s determination that Haitians and Syrians can now be safely deported back to those countries. The Supreme Court overturned the previous administration’s determination regarding the safety of deporting Haitians and Syrians in Mullin v. Doe. The Supreme Court decisions in Mullin v. Al Otro Lado and Mullin v. Doe did not invoke the Charming Betsy canon.

The Charming Betsy canon originates from an 1804 declaration by Chief Justice John Marshall in the case Murray v. Schooner Charming Betsy. 'An act of Congress ought never to be construed to violate the law of nations [today’s customary international law] if any other possible construction remains,' Chief Justice John Marshall said. The Declaration of Independence states that a decent respect to the opinions of mankind requires that they [the United States] should declare the causes which impel them to the separation from Great Britain.

The Supreme Court of the United States was established in 1789. The International Court of Justice is the primary judicial organ of the United Nations, and international courts are established by international agreements.

Academic research has examined the role of the Vienna Convention and the International Court of Justice in prior decades. Research titled The International Court of Justice's Use of the Vienna Convention in the Interpretation of Boundary Agreements: 2000-10 was published in 2012 in Journal of International Dispute Settlement. A study titled Jurisdiction and Compliance in Recent Decisions of the International Court of Justice was published in 2007 in European Journal of International Law.

The Supreme Court's rejection of the International Court of Justice's interpretation places the United States in a unique position among the 182 state parties to the Vienna Convention on Consular Relations. By maintaining that consular access rights can be waived if not raised during trial or direct appeal, the Court has repudiated the international body's rulings on the matter. This decision reflects a consistent judicial approach where the Supreme Court applies domestic legal principles to international treaties, often diverging from global consensus.

The implications extend beyond consular relations to other areas of international law, including refugee protections and extradition. The Court's previous rulings on the 1967 Refugee Convention and extradition treaties demonstrate a pattern of interpreting international obligations through a domestic lens. This approach contrasts with the Charming Betsy canon, which historically guided courts to avoid construing laws in ways that violate international law. The absence of this canon in recent decisions such as Mullin v. Al Otro Lado and Mullin v. Doe reflects the shift in how the judiciary engages with international legal norms.