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Foreign and International Legal Materials: A Practical Guide

Treaty Research Tasks

Treaties are defined by Article 2 of the Vienna Convention on the Law of Treaties.

Treaty research can involve different tasks depending on whether you are tracking down :

  • A treaty to which the United States is a party
  • The full text of a treaty for which you have a citation
  • A treaty index to determine if a treaty exists on a topic
  • The current status of a multilateral treaty

A Treaty to Which the United States is a Party

In the United States., the name “treaty” is reserved for an agreement made “by and with the advice and consent of the Senate.” U.S. Const. art. II, § 2, cl. 2. International agreements not submitted to the Senate for advice and consent are “executive agreements.” However, under international law, both types are considered treaties and therefore creating binding obligations.

To track treaties that have been submitted to the Senate for advice and consent, you can do your research on Unlike bills, which die at the end of a congress if they do not become law, treaties remain pending in the Senate until the Senate has completed its action by either agreeing to the resolution of advice and consent to ratification or by returning the treaty document to the President. You can find full text treaty documents or information about them on for all treaties submitted to the Senate since the 94th Congress (1975-1976). Treaties submitted prior to the 94th Congress are included if they were pending in 1975. 

The Office of Treaty Affairs from the U.S. Department of State is another authoritative resource for you to research U.S. treaty law and practice. To verify if the United States is currently a party to any treaties or international agreements, start from the Treaties in Force publication on the Department's website, which is published annually on January 1 of the calendar year. 

However, since the Treaties in Force is published only once a year on January 1, the information may not be entirely up to date. To find new treaties or international agreements that may have entered into force after the publication date, you will then check the Treaties and International Acts Series (TIAS) on the Department of State website for the period not yet covered by the Treaties in Force. You can access the TIAS by clicking the Agreement Texts tab. 

The Treaties and International Acts Series (TIAS) is an online series in which the text of treaties and international agreements to which the United States is a party is first published. Pursuant to 1 U.S.C. § 112a and 22 CFR 181.8, the Department of State is required to publish the text of those treaties and international agreements within 180 days after they enter into force. 

Treaty Index

Treaty Index is a finding tool for you to locate treaties by parties, subject matters, entry into force dates or other attributes. 

  • FLARE Index to Treaties is a free treaty index database that contains information on over 2,000 multilateral treaties concluded from the 1600s onwards and a number of bilateral treaties signed between 1353 and 1815, with links to the full text, where available.
  • If the multilateral treaty is deposited with the UN Secretary-General, browse the subject arrangement by chapters or use the Title Search in the "Status of Treaties" database.
  • HeinOnline’s World Treaty Library has one of the most comprehensive collections of treaty indexes.

Full Text Databases for Treaties

As a free resource, the United Nations Treaty Collection provides a few databases for you to find the text of most bilateral and multilateral treaties.

  • United Nations Treaty Series (1945 - present): UNTS contains all the treaties and international agreements registered with and published by the Secretariat of the United Nations since 1945. Based on Article 102 of the UN Charter, "Every treaty and every international agreement entered into by any Member of the United Nations . . . shall as soon as possible be registered with the Secretariat and published by it." This database contains all the digitized UNTS volumes and is fully searchable by title, keywords in text, entry into force date, party, etc. 
  • League of Nations Treaty Series (1920 - 1948): This is a collection of treaties registered with and published by the Secretariat of the League of Nations, the predecessor to the United Nations. 

To check the current status of a multilateral treaty, the United Nations Treaty Collection provides the following database: 

  • Status of Treaties Deposited with the Secretary-General (also known as the "Status of Treaties" or "MTDSG" database): This database contains the most current status of more than 560 multilateral treaties deposited with the Secretary-General of the United Nations. The treaties are grouped together by chapters (subject matters) such as human rights, disarmament and protection of the environment. For each multilateral treaty deposited with the Scretary-General, you will find the most current status info (number of parties, entry into force dates, RUDs, etc.). A link to the text of the treaty published in the UNTS is also provided.

For multilateral treaties not deposited with the Secretary-General of the United Nations, you will have to go somewhere else to find the most current status. Most multilateral treaties have official websites maintained by international organizations or non-profits. For example, the Hague Conference on Private International Law (HCCH) is an intergovernmental organization that administers dozens of international treaties in the area of private international law. You can find both the text and the current status of those treaties on the HCCH website. 

For a subscription-based database, HeinOnline's World Treaty Library is the most comprehensive one. 

  • HeinOnline - World Treaty Library: This library collects all the major treaty publications of the world, including Rohn’s treaty index, Dumont, Bevans, Martens, League of Nations and United Nations Treaty Series, and others. It currently has over 180,000 individual treaty records and covers the time period from 1648 to the present. 

Citations to Treaty Sources

If you have a citation to the treaty, check Table 4 of the Bluebook for the complete title of the source. You may then search the title in our Law Library Catalogue and find out how to locate that source. Our library holds most of the treaty sources listed on Table 4 either online or in print.