UPDATE: An Introduction to Sources for Treaty Research

By Mark Engsberg and Kwanghyuk (David) Yoo

Mark Engsberg is the Director of Library Services and Professor of Practice at the Hugh F. MacMillan Law Library at Emory University School of Law. Before coming to Emory Law, he worked at the Lillian Goldman Law Library at Yale Law School for eight years, where he served as the international and foreign law reference librarian and as head of reference. Professor Engsberg is active in professional legal and law librarianship organizations. Since 2005, he has served as editor-in-chief of the International Journal of Legal Information, published by the International Association of Law Libraries. Engsberg received his M.S.L.I.S. degree, as well as an M.A. and Ph.D. in English literature from the University of Illinois at Urbana-Champaign. He also holds a J.D. from Willamette University College of Law in Salem, OR, and a B.A. from Drury University in Springfield, MO.

Kwanghyuk (David) Yoo is a Law Librarian for Research Services at the Hugh F. MacMillan Law Library at Emory University School of Law. David received an S.J.D. and an LL.M. from the University of Iowa College of Law and an M.L.I.S. from the University of Iowa School of Library and Information Science. He also holds a Ph.D. and an M.A. in International Law, as well as a B.A. in law from Hanyang University School of Law in Seoul, South Korea.

Published May/June 2021

(Previously updated by Mark Engsberg and Mary Beth Chappell Lyles in October 2011 and in March 2016)

See the Archive Version!

1. Introduction

This brief guide provides a broad overview of the sources necessary or helpful to conduct treaty research. It covers background and definitional issues. It is not meant to be a "how to" guide, rather it provides a description of the tools necessary for researching both bilateral and multilateral treaties. This guide mostly covers information for researching treaties to which the United States is a party, but it also includes information useful for researching treaties to which the United States is not a party.

The first portion of the guide contains information about treaties, locating treaties, finding aids for treaty documents, and other related matters. The final segment of the guide provides an overview of electronic sources for conducting treaty research.

2. Treaties and International Agreements

What is a treaty? A treaty is a "formally signed and ratified agreement between two nations or sovereigns."[1] It is a record of the terms of agreement between two or more countries and is governed by international law.[2] Treaties or treaty-like instruments go by many other names as well, such as

Regardless of the various terms used to describe them, apart from some minor differences, they are all basically the same thing.[3]

A treaty binds only the parties to the treaty unless a third State expresses consent to be bound by the treaty.[4] The US government is bound by the provisions of a treaty only when the agreement has been submitted to the US Senate for advice and consent, 2/3 of the Senate vote to approve it, and the President ratifies it.[5] The entire process is called ratification.

International agreements are sometimes confused with treaties, though they are not treaties. Rather, they are executive in nature, can be approved with a simple majority vote of both houses of Congress, or may not even be submitted to Congress for approval. These documents directly govern or implement a great deal of US foreign policy, especially matters related to trade. International agreements are often preferred by various parties because they are often easier and more expeditious to obtain. After all, a 2/3 majority in the Senate—the proportion necessary to ratify a treaty—can be very difficult to achieve.[6]

3. A Brief Treaty Lexicon

When working with treaties, it is important to have a basic understanding of several key terms. As with many areas of the law and legal research, there is a specialized vocabulary, knowledge of which is essential for competent research and full understanding of treaty documents.[7] Below is a quick guide to some of the more important terms, or those terms one most frequently encounters in treaty research:

4. Locating Treaty Texts

There is no single correct way to do treaty research, but once one has become acquainted with the principal terms and sources of treaty documents it becomes a relatively simple matter to locate the text of a treaty. It can be a bit more difficult to discover the current status of a particular treaty. And it can be quite a challenge to find information about the negotiation or legislative history of a treaty, travaux preparatoire (unless the US is a party and you’re interested only in the US Senate ratification process).[17]

So where does one locate the text of a treaty or agreement? Where can one find the status and ratification information about a treaty? Sources for locating a treaty text where the United States is a party include the following:

There are many finding aids for treaties to which the US is a party. Here are six of the most important ones, along with a brief description of the salient features of each resource:

For treaties to which the US is a party, one should consult one or more of the following to locate information on the treaty's status, updating a treaty, and ratification of a treaty:

Keep in mind that treaties, which have not been ratified, do not necessarily die at the end of a US congressional session – they frequently carry over to subsequent sessions.

5. Multilateral Treaties

The following sources are helpful for locating the text of multilateral treaties:

Europe - EU founding treaties available online. Treaties the EU has entered into as a party are also published in the Official Journal of the European Union (OJ), L Series. These are available in electronic form from 1998 to the present. International Legal Materials (ILM) - The ILM has been published since 1962. It is a useful source for draft treaties, new, or unusual treaties. It is available in electronic format on LexisAdvance and WestlawNext. To find the status of a multilateral treaty, a good place to begin is with the Multilateral Treaties Deposited with the Secretary General. This is a print product but is also available online.

Finding the reservations of parties to a multilateral treaty can be a really tough job. Reservations often arise during the ratification process, and so they can be discovered in legislative histories (if any exist). For European treaties, one should consult the European Treaty Series. In the US, reservations can typically be found in the Congressional Record. For other countries, a researcher may need to contact a given country's diplomatic mission for information about that country's reservations for a specific treaty.

To learn about the ratification process or status of a treaty, remember that a country may be a signatory but not ratify a treaty. To determine the process of ratification outside the US, there are two main resources:

Most modern multilateral treaties create an administrative body called a secretariat. The secretariat is charged with the administration of the terms of the treaty. Secretariats can be useful sources for information relevant to treaty research. The secretariat is generally charged with:

Many secretariats have their own websites with links to important treaty documents and other information.[18] These websites are easily found using a general search engine.

6. Bilateral Treaties – US Not a Party

Researching bilateral treaties where the US is not a party can be very challenging indeed. First of all, every country deals with its bilateral treaties differently.[19] Perhaps the easiest way to find these treaty documents is in a commercial compilation of bilateral treaties by subject or online databases. Examples include

Some government websites publish indexes to treaties or the full texts of treaties. The United Kingdom, Australia, France, and the Netherlands have complete treaty information for those countries. Keep in mind that diplomatic missions of countries can also provide treaty information, so if one is having trouble locating the text of a bilateral treaty to which the United States is not a party, one could contact the official representative(s) of the government in question. A place to find contact information for embassies or consulates is Embassy World.

For treaties to which the US is a party that you cannot find in other sources, you can contact the country desk at the Department of State or Department of Commerce.

7. Electronic Resources for Treaty Research

This guide concludes with a very brief survey of some of the more important electronic resources for treaty research. While we have included links to the electronic platforms for a number of resources listed above, what follows is a listing of materials that did not easily fit into the descriptions or organizational scheme. Electronic access to important legal information of all kinds has increasingly become the norm. This is particularly true with respect to international treaty information. Because of the dynamic nature of the digital world of treaty information, the following section does not pretend to be comprehensive, and we are sure the guide overlooks any number of excellent electronic resources. We strive merely to represent the nature and variety of electronic resources for treaty information.

United Nations and United States treaty sources are perhaps the easiest to find in electronic formats. In fact, it is probably fair to say that the UN is the leader in electronic access.[22] Below is a sampling of several free Internet resources for treaty information. Included in this section are resources for United Nations treaties, United States treaties, and European and Organization of American States treaties. The final section contains information about several subscription or proprietary databases, excluding Lexis and Westlaw.

7.1. Free Internet Resources

United Nations Treaty Collection

UN Official Document System

UN Digital Library - online catalogue of United Nations documents and publications indexed by the Dag Hammarskjőld Library.

Treaty Research Guide of the Dag Hammarskjőld Library

Legal Research Guide of the Library of the UN Office in Geneva

World Legal Information Institute

Statutes at Large

US Department of State

US Trade Representative

Other sites to consider:

ASIL Electronic Resource Guide - Look Guide to Public International Law that includes an instruction to treaty research.

Use www.google.com or any other search engine to locate treaties. This is the most imprecise method (a broadcast method), and you need to be particularly mindful of the varied quality of the sources you get from this kind of search. A general search for “treaty” on Google currently results in over 56,300,000 hits. Most of these sites are worthless, but some may be quite helpful. Use the advanced search tool to help focus your search.

7.2. Subscription Databases

Access UN




[1] Black's Law Dictionary, 15c (11th ed. 2009).

[2] Vienna Convention on the Law of Treaties of 1969, art. 2, §1(a) (defining a treaty as “an international agreement concluded between States in written form and governed by international law, whether embodied in a single instrument or in two or more related instruments and whatever its particular designation”).

[3] See United Nations Treaty Handbook, Glossary (providing the definition of these treaty-like instruments).

[4] Vienna Convention on the Law of Treaties of 1969, art 34.

[5] U.S. Const. art. II, § 2, Cornell Law School Legal Information Institute.

[6] See International Agreements and U.S. Law, ASIL Insights (1997) (providing a more complete description of the difference between treaties and international agreements).

[7] See United Nations Treaty Collection (describing treaty terms in further detail).

[8] Black's Law Dictionary, 16c (11th ed. 2019).

[9] Id. at 18c.

[10] See United States Treaty Collection

[11] See International Agreements and U.S. Law, ASIL Insights (1997) (providing a more complete description of the difference between treaties and international agreements).

[12] Black's Law Dictionary, 1827 (11th ed. 2019).

[13] See United Nations Treaty Handbook, Glossary 69.

[14] Black's Law Dictionary, 15c (11th ed. 2019).

[15] Id.

[16] Id. at 1866.

[17] See Jonathan Pratter's excellent guide to travaux preparatoire on GlobaLex.

[18] See, for example the website for the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).

[19] Stephanie Weigmann has created a very useful guide for locating treaties where the US is not a party. Her guide can be found at https://www.llrx.com/2001/05/features-researching-non-u-s-treaties-and-agreements/.

[20] The site is administered by Glenda Pearson at the University of Washington. According the to the site, The World Treaty Index provides access to over 55,000 treaties of the 20th century, from sources ranging from the United Nations Treaty Series to various national indexes, gazettes, and official files. This site has temporarily resided in the new WTI site since a complete site resign in 2010. The updated page will provide a comprehensive database of over 75,000 treaties in the new WTI site.

[21] The EISIL is temporarily unavailable due to ongoing upgrade to EISIL 2.0.

[22] UN treaty documents are typically found in all six official languages: Arabic, Chinese, English, French, Russian, and Spanish.