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International Legal Research: Treaty Interpretation

This Guide covers essential print and electronic resources for researching international and foreign law.

Treaty Interpretation

After finding the text of a treaty, it is sometimes important to explore how the treaty came about, or to learn how it has operated since the time of its signing, or even to know the role of treaties in general in international law. In addition to the treaty citators, the following sources provide that type of information.

A.    The Digest of International Law is a State Department publication that began in 1886. Earlier Digests are commonly known by the names of their editors-- i.e., Wharton’s (3 volumes, 1886), Moore’s (8 volumes, 1906), Hackworth’s (8 volumes, 1940-44), and Whiteman’s (15 volumes, 1963-73) (KZ235 .W55 1963; also in fiche under “Department of State, Digest of International Law”). After 1973, the Digest of International Law became the Digest of U.S. Practice in International Law (KZ21.D54). Despite its title, the Digest is not like the West digests for researching the case law of the U.S. and the fifty states. Rather the Digest is itself an important source of the practice of the United States in international law. It contains excerpts from treaties, relevant articles, and court decisions. The Digests are not cumulative, so later editions do not supersede the earlier ones. Due to budgetary constraints, publication of the Digest was suspended from 1989 to 1999. The State Department recently renewed the annual publication of the Digest in electronic format starting with the 2000 edition. All of the historical Digest editions listed above are available digitally in HeinOnline’s Foreign & International Law Resources Database.

B. The Restatement of the Law, Third: Foreign Relations Law of the United States (KF4651 .Am35 3d) has a large section on the nature, operation, and interpretation of international agreements. Both the Digest and Restatement constitute evidence of custom, which is another source of international law in addition to treaties.

C. American International Law Cases 1st series 1783-1968, 2nd series 1979-1989, 3rd series 1990- cover all areas of international law, throughout American history. There is a subject index for the first and second series and and a table of cases for all series. International Law Reports (KZ199 .I58) contain english translations of decisions of non-U.S. national courts related to public international law. A consolidated subject index and table of treaties provide access to the decisions. ILR is now available electronically via Justis

D. Similar to the legislative history of a statute, the ratification history of a treaty can aid in the interpretation of that treaty. For a discussion of this process, see, for example, Gwendolyn Folsom, “Usable Background for Treaty Interpretation,” in Legislative History: Research for the Interpretation of Laws (KF 425 .F73 1979). Useful sources for U.S. treaty interpretation include the Senate Treaty Documents (Y 1.1/4), which consist of the pre-ratification text of treaties submitted by the President to the Senate for its advice and consent as well as the President’s comments. The views of the Senate Committee on Foreign Relations on pending treaties and conventions are also important in terms of ratification history and treaty interpretation. Such views are set forth in the Senate Executive Reports (Y 1.1/6). The Congressional Information Service (CIS) Annual Indexes (KF49 .C62) provide subject and title indexes for these documents, which are available in microfiche. Digital access is available via the Library’s subscription to Proquest Congressional.

E. General principles of treaty interpretation are discussed in treatises like Oppenheim’s International Law (KZ3264.A3 .I57 1992) and Modern Treaty Law and Practice (KZ1301 .A93 2007)

F. The negotiating or drafting history of a treaty (“travaux preparatoires”) differs from the ratification history but may also be of interest to researchers. The travaux preparatoires are a supplementary means of treaty interpretation under the Vienna Convention on the Law of Treaties, Article 32, May 23, 1969, 1155 U.N.T.S. 331, 8 I.L.M. 679. As with other aspects of treaty research, sources on interpretation can be found by using the online catalog. Search the JMLS Library’s catalog, for example, by subject for “Treaties -- Interpretation and Construction” or run a keyword search in Worldcat (available via FirstSearch) for “travaux preparatoires”.        

Ratification History

A Senate Treaty Document is actually a “packet” consisting of President’s Transmittal Message to Senate, Letter of Submittal from Secretary of State to President and text of proposed agreement. The treaty is then referred to the Senate Foreign Relations Committee for consideration. Hearings may also be held and representatives of the Administration may testify. Such testimony constitutes part of the ratification history.

If the Senate Foreign Relations Committee votes to recommend the treaty to the full Senate for its advice and consent, it sends the agreement to the Senate accompanied by an Executive Report. The Senate Executive Report contains the Committee’s recommendation, a summary of the agreement and sometimes a detailed article by article analysis of the agreement. Debate on the Senate floor is recorded in the Congressional Record. The President must consent to ratify, even after the Senate has given its advice and consent. All of the resulting documentation (Document, testimony, Report, debate) constitutes part of the ratification history.

Note: do not confuse this ratification history with the negotiating history of the agreement, also known as the “travaux preparatoires”. The drafting history constitutes a a supplementary means of interpretation, per the Vienna Convention on the Law of Treaties. Also, while there are some similarities, don’t confuse the ratification history of a treaty with the legislative history of a statute. Statutes and treaties differ primarily in that a treaty is an agreement between two nations, so another sovereign state is involved.

Reservations=modifications of treaty obligations, without necessarily changing treaty language; Declarations=statements of purpose, policy or position; Understandings=interpretative statements that clarify or explain and are consistent with treaty oblibations. RDUs may be hard to find due to the long gap in publication of U.S. treaties. Sometimes, researchers must resort to the Senate Treaty Documents or Executive Reports and the Congressional Record to find the RDUs. UST and TIAS are the only sources that can be cited as definitive authority. So the lag in publication is a dilemma. See Pratter, Jonathan. How to Do Research on the Interpretation of U.S. Treaties, Presentation at AALL Meeting, July, 2005 A recent law now requires the Secretary of State to publish on the State Department website all treaties and agreements proposed to be published in UST (PL 108-458 codified at 1 U.S.C. 112a(d)).

For more see: Researching U.S. Treaties and Agreements By Marci Hoffman