International Law and Agreements: Their Effect Upon U.S. Law

Publication Date: August 2004

Publisher: Library of Congress. Congressional Research Service

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Research Area: Law and ethics

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Abstract:

This report provides an introduction as to the roles that international law and agreements play in the United States. International law is derived from two primary sources -- international agreement and customary practice. Under the U.S. legal system, international agreements can be entered into either pursuant to a treaty or via executive agreement. The United States Constitution allocates primary responsibility for entering such agreements to the Executive branch, but Congress also plays an essential role. First, in order for a treaty (but not an executive agreement) to become binding upon the United States, the Senate must provide its advice and consent to treaty ratification by a two-thirds majority. Secondly, Congress may authorize congressional-executive agreements. Thirdly, many treaties and executive agreements are not self-executing, meaning that in order to take effect domestically, implementing legislation is required to provide U.S. bodies with the authority necessary to enforce and comply with an international agreement's provisions.

The status of an international agreement within the United States is dependant upon a variety of factors. Self-executing treaties have a status equal to federal statute, superior to state law, and inferior to the Constitution. Depending upon the nature of executive agreements, they may or may not have a status equal to federal statute. In any case, self-executing executive agreements have a status that is superior to state law and inferior to the Constitution. Treaties or executive agreements which are not self-executing have been understood by the courts to have limited status domestically; rather, the legislation or regulations implementing these agreements are controlling domestically.

The effects of the second source of international law, customary international practice, upon the United States are more ambiguous and controversial. While there is some Supreme Court jurisprudence finding that customary international law is part of U.S. law, conflicting U.S. statutes remain controlling. Customary international law is most clearly recognized under U.S. law via the Alien Tort Claims Act (ATCA), which establishes federal court jurisdiction over tort claims brought by aliens for violations of "the law of nations." The scope of this statute was recently clarified by the Supreme Court in Sosa v. Alvarez-Machain.

Recently, there has been some controversy concerning references made by U.S. courts to foreign laws or jurisprudence when interpreting domestic statutes. Historically, U.S. courts have on occasion looked to foreign jurisprudence for persuasive value, but foreign jurisprudence never appears to have been thought of as binding. Though U.S. courts will likely continue to refer to foreign jurisprudence, where, when, and how significantly they will rely upon it is difficult to predict.