Treaties Summary

  • Last updated on November 11, 2022

Binding, normally written, international agreements between or among governments of states and/or intergovernmental organizations.

It should be noted that the U.S. Constitution itself takes the form of a treaty and required the ratification of the conventions of nine states to enter into force. In dealing with treaties, the Supreme Court is guided by the language of the Constitution and by long-standing practice that has emerged between the executive and legislative branches. The treaty clause of the Constitution is found in Article II, section 2. It stipulates 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.” The Court’s judicial power, as defined in Article III, section 2, extends to “all Cases…under this Constitution, the Laws of the United States, and Treaties made or which shall be made, under their authority.” Finally, the supremacy clause of Article VI of the Constitution stipulates that “This Constitution, and the Laws of the United States which shall be made in Pursuance thereof; and all Treaties made, or which shall be made, under the Authority of the United States, shall be the supreme Law of the Land.” This is the extent of the language in the Constitution regarding treaties. It establishes that the president is the chief maker of treaties and that the Senate exercises a role of advice and consent. The Court has no direct role in the treaty-making process, other than in interpreting treaties and statutes in cases brought before it and deferring to and applying them as the supreme law of the land.

The Constitution does not actually define the term “treaty.” At the time of the Constitutional Convention, however, treaties were understood to include any international agreement duly entered into by heads of state. Indeed, from the standpoint of international law, any agreement the president enters into binds the United States, regardless of whether it is formally referred to as a treaty or any one of three dozen other terms, including charter, convention, covenant, and pact. However, a distinction in the internal practice of the United States emerged from the outset in the practice of presidents and the Senate. This distinction is rooted in the fact that although the Constitution does not define the term “treaty,” it does stipulate that the president has the power to make a treaty with the consent of the Senate. The Constitution does not forbid a president from entering into agreements with other governments without the consent of the Senate. Although such an agreement would not be a treaty under the language of the Constitution, it would nonetheless still constitute binding international law. Such agreements are referred to as “executive agreements.”

Executive Agreements and Treaties

In the United States, both executive agreementsExecutive agreements and treaties were routinely entered into by presidents. Presidents brought treaties before the Senate for its advice and consent before they formally ratified them. However, presidents also entered into agreements as they saw fit in conducting U.S. foreign policy, without the formal advice and consent of the Senate. Indeed the Senate acquiesced in this presidential practice as it has no constitutional authority to negotiate with foreign states and the president is better equipped and constitutionally authorized to conduct foreign relations and make treaties. In addition, for many routine matters of foreign affairs, the Senate can be easily overwhelmed with unnecessary work related to the treaty approval process.

In early practice, presidents brought major agreements to the Senate for approval, using executive agreements much less frequently. In the twentieth century, however, and especially after World War II, the use of executive agreements has skyrocketed, along with the number of international agreements. For every treaty entered into, nearly twenty executive agreements are signed. Proliferation in the use of executive agreements eventually caused Congress to pass the Case ActCase Act in 1972. This act attempted to ensure timely presidential consultation with Congress in the exercise of the treaty-making power through executive agreements.

The Case Act, reflecting long-standing actual practice, distinguished between congressional-executive agreements, in which a president seeks prior or subsequent authority by a joint resolution of both legislative chambers to negotiate and sign agreements, and sole or pure executive agreements, which the president enters into without any senatorial action or joint legislative approval. The Case Act requires the president to advise Congress in writing of all such agreements, even of agreements the president believes must be kept secret to protect national security, although these need not be transmitted with public notice.

Although the Court did not enter into the struggles by Congress to ensure its proper advisory role in the treaty-making process, as this is properly a matter of adjustment between the executive and legislative branches, it formally acknowledged in the United States v. Pink[case]Pink, United States v.[Pink, United States v.] (1942) that executive agreements are equally as valid as treaties in their domestic effects. It also ruled that the president and Congress may distinguish between treaties and executive agreements. In the case of Weinberger v. Rossi[case]Weinberger v. Rossi[Weinberger v. Rossi] (1982), the Court determined that Congress, in using the term “treaty” in a statute intended to prohibit discrimination against U.S. nationals seeking overseas employment at U.S. military bases unless permitted by a treaty, actually meant to include both formal Article II treaties requiring senatorial approval and executive agreements. By actual practice, Congress had tolerated presidential executive agreements with foreign governments that permitted discrimination against U.S. nationals in favor of foreign nationals who sought employment overseas, and the Court upheld the president’s authority under both the Constitution and the congressional statute and practice to enter into such an agreement.

The Supremacy Clause

The Court has spoken definitively on the issue concerning the constitutional provision that treaties are the supreme law of the land and that they take precedence over prior federal statutes and the legislative enactments of the various states. In the case of Missouri v. Holland[case]Missouri v. Holland[Missouri v. Holland] (1920), the Court held that a treaty between the United States and Great Britain on behalf of Canada regulating the hunting of migratory birds took precedence over Missouri statutes permitting the hunting of Canadian migratory geese. Especially telling in this case was that federal game wardens had previously attempted to enforce a federal statute regulating the hunting of migratory birds. Missouri successfully challenged this federal intrusion on grounds that it violated the reserved rights of states under the constitution to regulate such matters. However, when the president of the United States entered into a treaty with Great Britain and when Congress enacted a statute to enforce this treaty obligation, the situation changed. When Missouri again challenged the federal government’s right to enforce federal statutes that conflicted with its own state law, the Court held that the federal government, and its agent Holland, had acted constitutionally.

The court cited the supremacy clause, which stipulates that treaties are the supreme law of the land. Because only the federal government not the states has treaty powers, treaties automatically take precedence over conflicting provisions of state law. In this case, the treaty regulating migratory birds had been given domestic legal effect through the passage of an implementing federal statute. What the latter alone could not accomplish constitutionally was constitutionally valid when effected pursuant to a treaty obligation.


Under international law, any treaty (or executive agreement) is binding on states and takes precedence over any prior or subsequent domestic law. Governments, from the standpoint of international law, may not use domestic legislation as a means of avoiding international treaty obligations. In U.S. practice, however, problems arise because the Court has held that treaties (like statutes) that violate the Constitution are invalid and that a statute that conflicts with a prior treaty supersedes the latter. Therefore, conflicts may arise between U.S. international obligations and internal legal requirements. In the case of Reid v. Covert[case]Reid v. Covert[Reid v. Covert] (1957), the Court held that military wives who killed their husbands on U.S. foreign military bases had a constitutional right under the Fifth and Sixth Amendments to an indictment by a civilian grand jury and to a trial by jury of their peers. These rights, the Court held, were superior to either the federal statute or the executive agreements that called for courts-martial under the Uniform Code of Military Justice in such cases. This case clearly asserted the superiority of the Constitution over the terms of a treaty.

Whereas the Missouri v. Holland case illustrated that a treaty takes precedence over the prior legislation of states, the Court consistently held that a treaty may be abrogated in whole or in part by subsequent federal statutes. The Court routinely ruled, as in Reid v. Covert, that it is bound to apply whichever treaty or statute is most recent in time. Under the Constitution, treaties and statutes are treated in full parity as sources of law and obligation. Therefore, when a conflict in law arises between a treaty and a statute, the Court will apply the most recently enacted one. When the statute is the most recent and controlling source, this may place the United States in dereliction of its international obligations and may require it to pay due compensation; however, from the standpoint of domestic law, the statute would take precedence over the treaty. To avoid such problems, the Court attempts to resolve apparent conflicts between treaties and statutes so as to give effect to both, as it asserted in Whitney v. Robertson[case]Whitney v. Robertson[Whitney v. Robertson] (1888).

Though the Court does on occasion rule in matters involving treaties, the power and practice of making treaties falls within the purview of the political and policy-making branches. The Court was not intended by the Constitution to exercise an aggressive oversight role in matters that so directly relate to national security, the national interest, and the challenge of fashioning effective foreign policy in the face of changing needs. Therefore, the president has exercised the lead role in this area to varying degrees with a cooperative or rebellious Congress.

Further Reading
  • One place to start a study of this subject is with general reference works on treaties, such as Charles Phillips and Alan Axelrod’s Encyclopedia of Historical Treaties and Alliances (2d ed. New York: Facts On File, 2005) and U.S. Laws, Acts, and Treaties (3 vols. Pasadena, Calif.: Salem Press, 2003), edited by Timothy L. Hall. Although relatively few works focus on the Supreme Court’s activity in the treaty-making area, numerous works on international law, constitutional law, and the U.S. political process cover the subject. One of the most recent and comprehensive assessments is Randall W. Bland’s The Black Robe and the Bald Eagle: The Supreme Court and Foreign Policy, 1789-1960 (Bethesda, Md.: Austin & Winfield, 1998). Also useful is Louis Henkin’s Foreign Affairs and the Constitution (Mineola, N.Y.: Foundation Press, 1996). Two excellent international law texts containing chapters devoted to treaties and executive agreements in U.S. practice are Gerhard von Glahn’s Law Among Nations (New York: Macmillan, 1997) and William R. Slomanson’s Fundamental Perspectives on International Law (New York: West Publishing, 1995). A lengthy and classic treatment on the international law of treaties is A. McNair’s The Law of Treaties (Oxford: Clarendon Press, 1961). Useful sections dealing with Supreme Court cases on the treaty powers can be found in treatments on U.S. constitutional law such as Ronald D. Rotunda and John E. Nowak’s Treatise on Constitutional Law: Substance and Procedure (Vol. 1, St. Paul, Minn.: West Publishing, 1992), as well as Randall W. Bland and Joseph Brogan’s Constitutional Law and the United States (Bethesda, Md.: Austin & Winfield, 1999).

Constitution, U.S.

Executive agreements

Foreign affairs and foreign policy

International perspectives on the Court

Missouri v. Holland

National security

Native American treaties

Presidential powers

Categories: History