What are “Treaties” under U.S. Law?
Date of Information: 01/01/2025
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What is a “Treaty?”
In general, treaties are binding agreements between nations. As such, they become a part of international law.
However, it is important to remember that the process for entering into a treaty, the degree to which the treaty is binding on any particular country, and the effect that the treaty will have on a signatory country’s domestic laws are slightly different in every country. The notion of a treaty implies that each country entering into the treaty is sovereign, i.e., the signatory country is “endowed with supreme authority.” SOVEREIGN, Black's Law Dictionary (12th ed. 2024). There is no higher authority over the participants to settle precisely what a treaty is or what the effects of a particular treaty will be. Consequently, the force constraining the parties to a treaty is nothing more than the willingness of the other sovereign participants to restrain their own conduct in light of another participant's conduct. Invariably, there will be differences in interpretation. Frequently, signatories will attempt to get away with as much as they can under the treaty's terms without provoking the other signatories into retaliation. Smoothing over those differences in interpretation and interests under existing treaties is much of the work of the international diplomatic corps.
What is a “Treaty” to the United States
What constitutes a “treaty” under U.S. law is quite specific. The United States Constitution provides that the president "shall have Power, by and with the Advice and Consent of the Senate, to make Treaties, provided two-thirds of the Senators present concur" (Article II, Section 2).
In general, a proposed treaty is negotiated by the U.S. State Department as agents of the President of the United States. Once the treaty’s language is agreed upon by both the U.S. delegation and the foreign delegation or delegations, the draft treaty is taken to the U.S. Senate for approval.
The draft treaty is first considered by the Senate Committee on Foreign Relations, which prepares a recommendation on whether the Senate should approve it. The issue of approval is brought to a vote in the Senate as a “resolution.” If the resolution passes, then the approved treaty goes back to the Executive Branch, which exchanges the instruments of ratification with the foreign power(s) on behalf of the United States as a whole.
What Effect do Treaties Have on U.S. Law?
In general, treaties to which the United States is a party also have the force of federal legislation, forming part of what the Constitution calls ''the supreme Law of the Land.'' However, the precise effect that a treaty has on U.S. domestic law depends on whether the treaty is “self-executing.”
The U.S. Supreme Court “has long recognized the distinction between treaties that automatically have effect as domestic law, and those that—while they constitute international law commitments—do not by themselves function as binding federal law.” Medellin v. Texas, 552 U.S. 491, 504 (2008). “[A] treaty is ‘equivalent to an act of the legislature,’ and hence self-executing, when it ‘operates of itself without the aid of any legislative provision.'“ Id., at 505 (quoting Chief Justice John Marshall’s opinion in Foster v. Neilson, 27 U.S. 253 (1829) (1829)). “When, in contrast, treaty stipulations are not self-executing they can only be enforced pursuant to legislation to carry them into effect. In sum, while treaties may comprise international commitments, they are not domestic law unless Congress has either enacted implementing statutes or the treaty itself conveys an intention that it be self-executing and is ratified on these terms.” Id. (some internal punctuation and citations omitted).
If a treaty is drafted to be self-executing, it immediately becomes binding on the United States as if it were an act of law passed by the whole Congress and signed by the President of the United States. “Our Nation's obligations arising from multiple treaties with a neighbor in our region of the world are paramount. Duly enacted treaties are, after all, the law of the land and fully enforceable under the Supremacy Clause.” Matter of Extradition of Ricardo Alberto Martinelli Berrocal, 263 F. Supp. 3d 1280, 1306 (S.D. Fla. 2017) (citing Sanchez–Llamas v. Oregon, 548 U.S. 331, 346–47(2006)).
If the treaty is not self-executing, it is incumbent upon Congress to pass legislation effectuating the treaty's terms. A good example is the Refugee Act of 1980, which brought the refugee and asylum laws into line with the with U.N. Refugee Convention of 1951 and the 1967 Protocol.
However—notably—“no agreement with a foreign nation can confer power on the Congress, or on any other branch of Government, which is free from the restraints of the Constitution.” Boos v. Barry, 485 U.S. 312, 324 (1988). Consequently, “the United States government must, in carrying out its treaty obligations, conform its conduct to the requirements of the Constitution, and that treaty obligations cannot justify otherwise unconstitutional governmental conduct.” Plaster v. United States, 720 F.2d 340, 348 (4th Cir. 1983).
Other Forms of International Agreements.
The Senate has considered and approved for ratification all but a small number of treaties negotiated by the president and his representatives. In some cases, when Senate leadership believed a treaty lacked sufficient support for approval, the Senate simply did not vote on it, and the president eventually withdrew it. However, that does not mean that the agreement between the President of the United State and the foreign power is entirely void.
In those events, the President can still form an agreement with a foreign nation. These are called "executive agreements." However, executive agreements do not have the effect of law within the United States. Moreover,tThey will only be binding on the United States to the extent that the President has the authority to order compliance with the agreement under his own authority. For more information on the powers of the President of the United States to regulate foreign relations, see the CIL Guide on that topic.