International agreements to which the United States is a party are a source of law in the United States. The Supremacy Clause of the Constitution says so: "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 ...." Legal researchers, then, should know as much about researching international agreements as they do about researching the other sources of U.S. law. The purpose of this guide is to show how to do basic research on international agreements of the U.S., and also how to research international agreements when the U.S. may not be a party.
The guide covers these main topics: 1) Researching U.S. international agreements, including finding the citation to a U.S. international agreement, finding the text of U.S. international agreements, and determining the current status of U.S. international agreements; 2) Researching multilateral agreements, including finding the citation to a multilateral agreement, sources for the full text of multilateral agreements, determining the current status of multilateral agreements, and finding the drafting history of a multilateral agreement, often known by the French phrase travaux préparatoires.
An international agreement is an agreement between or among sovereign states (and sometimes an international organization) in writing and governed by international law, whatever its particular designation. The last phrase indicates that the particular name of the agreement -- it could be treaty, convention, covenant, charter, compact, accord, agreement, statute, exchange of notes, etc. -- does not affect its status as an international agreement under international law.
International agreements can be bilateral (between two parties) or multilateral (among three or more parties).
The practice of the U.S. distinguishes between treaties and executive agreements. The Treaty Clause of the Constitution -- Article II, Section 2, Clause 2 -- vests the power to make treaties in the President, acting with the advice and consent of a two-thirds majority of the Senate. The great majority of U.S. international agreements are not treaties, but executive agreements -- agreements that are entered into by the executive branch that are not submitted to the Senate for advice and consent. Executive agreements are not mentioned in the Constitution, but they are considered binding U.S. international agreements under Supreme Court case law and as a matter of historical practice. Federal law requires the executive branch to notify Congress of executive agreements (Case-Zablocki Act of 1972, 1 U.S.C. § 112b).
Treaties in Force, 2020 edition + 2021 Supplement
Treaties in Force is the annual statement of U.S. international agreements in force as of January 1 of the current year. It is published by the U.S. State Department and is available in PDF on the State Department's website. Treaties in Force is divided into bilateral and multilateral sections. The bilateral section is organized by the name of the other state party and subdivided by subject. The multilateral section is organized by subject. Treaties in Force provides citations to the full text of the agreements it lists. However, not every agreement listed in Treaties in Force is published. Some entries have the designation "NP" where the citation would be. This means that the agreement is not printed in the Treaties and Other International Acts Series (T.I.A.S.), the main treaty series currently published by the U.S. State Department. Moreover, some entries in Treaties in Force have a blank after the designation T.I.A.S., which apparently indicates that the agreement has not yet been published, though it is intended at some point to be published in T.I.A.S.
Treaties and Other International Acts Series (T.I.A.S.)
T.I.A.S. is the current series for the publication of U.S. international agreements. It covers the period 1946-present, and is available in PDF on the State Department website from 1981. Agreements are published separately as individual pamphlets. It should be noted that some international agreements of the U.S. (often treaties that have received the advice and consent of the Senate) are not published in T.I.A.S., which publishes mainly executive agreements.
Treaties that are submitted to the Senate for advice and consent are sent in Senate Treaty Documents, which are referred to the Committee on Foreign Relations for consideration and reporting to the full Senate. Treaty Documents are available on Congress.gov from 1975. The Blue Book allows citation to Treaty Documents.
United States Treaties and Other International Agreements (U.S.T.)
U.S.T. publishes in bound volumes agreements that first appeared in T.I.A.S. It covers the period 1950-1984. U.S.T. is available on HeinOnline in the U.S. Treaties and Agreements Library and in print in the stacks at JX231 A34.
International Legal Materials (I.L.M.)
I.L.M. is published by the American Society of International. It publishes significant international primary documents of all kinds, including international agreements. The Blue Book allows citation to I.L.M. It is available on HeinOnline and in print in the stacks at JX 68 I5. I.L.M is also on Westlaw and Lexis.
Treaties and executive agreements of the U.S. entered into up to 1950 are published in the sources listed here.
Treaty Series (T.S.)
Treaty Series publishes treaties of the U.S. from 1908 to 1945. It is available in microfiche (KZ231 T74) and on HeinOnline (1929-1945).
Executive Agreement Series (E.A.S.)
Executive Agreement Series publishes executive agreements of the U.S. from 1929 to 1945. It is available in microfiche (KZ231 E93) and on HeinOnline.
Statutes at Large (Stat.)
Up to 1950 treaties of the U.S. were published in Stat. Stat. is available in print on stack 203 in the 2nd floor reading room. Online it can be found on the GovInfo website and on HeinOnline.
Treaties and Other International Agreements of the United States of America, 1776-1949 (Bevans)
This handy compilation of U.S. international agreements, both bilateral and multilateral, is known as Bevans for the name of the compiler. Bevans is available in print in the stacks at JX236 1968. It is also on HeinOnline.
Treaty Action in the Senate (U.S. Senate website)
This page has links to Treaties Received during the current Congress, to Treaties Approved during the current Congress, and to Treaties with Floor Status Actions during the current Congress.
Treaties Pending in the Senate (U.S. State Department website)
Treaties, unlike bills for legislation, do not expire at the end of a Congress if not acted upon. They remain pending in the Senate Foreign Relations Committee. This page lists those treaties that have been submitted and and are pending, with links to the relevant Senate Treaty Document.
Treaties in Force, 2020 edition + 2021 Supplement
Agreements that are listed in Treaties in Force are in force for the U.S. The multilateral section of Treaties in Force usually lists the depositary of an agreement with a link to the depositary website. There a researcher can find information about other parties to the agreement as well as the text of reservations, understandings and declarations that have been entered.
(This section derives from Georgetown Law Library's Treaty Research Guide.)
These are links to online collections of international agreements that some U.S. government agencies make available in their respective fields of competence.
Arms Control
State Department -- Bureau of Arms Control, Verification and Compliance
Focus Areas (Spotlight Treaties and Agreements)
Environmental
Environmental Protection Agency
Selected Multilateral Environmental Instruments in Force for the U.S.
Intellectual Property
Department of Commerce -- Office of Trade Agreements Negotiation and Compliance
Intellectual Property Rights Agreements
International Investment
State Department -- Bureau of Economic and Business Affairs
United States Bilateral Investment Treaties
International Trade
Office of the U.S. Trade Representative
Trade & Investment Framework Agreements
Department of Commerce -- Office of Trade Agreements Negotiation and Compliance
Private International Law
State Department -- Office of the Legal Adviser
Dispute Settlement: Arbitration, Mediation and Judgments
Taxation
Internal Revenue Service
United States Income Tax Treaties -- A to Z
Treasury Department
Recent Income Tax Treaties and Tax Information Exchange Agreements (TIEAs)
The Flare Index to Treaties is produced by the Institute of Advanced Legal Studies at the University of London. It is online and free to use. The index has information on over 2000 multilateral agreements, including detailed information on where an agreement is published. Where the text of an agreement is available online, links are provided. Other indexes to treaties are available, but the Flare Index to Treaties is recommended.
United Nations Treaty Series (U.N.T.S)
Article 102 of the United Nations Charter requires member states to register their international agreements with the UN Secretariat, which is required to publish them. This is the origin of U.N.T.S., which now has more than 3000 volumes. It publishes both bilateral and multilateral agreements. U.N.T.S. is available for free online in the United Nations Treaty Collection.
League of Nations Treaty Series (L.N.T.S.)
L.N.T.S. is the predecessor of U.N.T.S. In 205 volumes in print it covers the period 1920-1946. L.N.T.S. publishes both bilateral and multilateral agreements. It is available for free online in the United Nations Treaty Collection.
Consolidated Treaty Series (Consol.T.S.)
C.T.S. is published commercially, but is considered a standard source for the publication of international agreements. In 230 volumes in print it covers the period 1648-1919. C.T.S. publishes both bilateral and multilateral agreements. It is available in print in the stacks at JX120 P3. The three treaty series listed here cover a continuous period of time from 1648 to the present.
Multilateral Treaties Deposited with the Secretary-General
Multilateral Treaties Deposited with the Secretary-General provides information on over 560 multilateral agreements for which the UN Secretary-General acts as the depositary. It is divided into 29 chapters by subject and is available for free online in the United Nations Treaty Collection. Each entry provides basic information about the agreement: date and place concluded, date of entry into force, number of parties and signatories, location of the text in U.N.T.S. and a link to the certified true copy of the agreement in pdf. There is an alphabetical list of participants (parties or signatories) with the relevant dates and with links to the text of reservations, understandings, declarations or objections for parties that entered them.
Other Intergovernmental Organizations That Act As Treaty Depositaries
(This section derives from Georgetown Law Library's Treaty Research Guide.)
The African Union website has a page titled OAU/AU Treaties, Conventions, Protocols & Charters. For each instrument listed there is a link to a Status List.
The more than 220 international agreements adopted under the auspices of the Council of Europe are listed on the Council of Europe's website. For each instrument there are links to an alphabetical table of ratifications and signatures and to a statement of reservations, understandings and declarations that were entered.
Hague Conference on Private International Law
For each of the more than 40 conventions concluded under the auspices of the Hague Conference there is a status table that has an alphabetical list of parties to a convention with the relevant dates and links to the text of reservations, understandings or declarations that were entered.
International Atomic Energy Agency
For each of the 18 agreemements concluded under the auspices of the IAEA there is a status table with an alphabetical list of parties to an agreement with the relevant dates. Under the title of each agreement there is a separate link to the text of reservations, understandings, declarations or objections that were entered.
International Civil Aviation Organization
For each of the more than 50 agreements concluded under the auspices of the ICAO there is a status table with an alphabetical list of parties to an agreement with the relevant dates and notes as to reservations, understandings and declarations that were entered.
International Committee of the Red Cross
The ICRC keeps track of over 80 international agreements and other instruments dealing with international humanitarian law. For the international agreements that states can become a party to there is a link to an alphabetical list of state parties with relevant dates and links to the text of reservations, understandings and declarations that were entered.
International Labour Organization
For each of the over 190 conventions entered into under the auspices of the ILO there is an alphabetical ratification table that shows which countries have become a party to a convention with relevant dates.
International Maritime Organization
The IMO produces a book titled Status of IMO Treaties, dated 17 June 2021, which is available for free online in pdf. The book provides "comprehensive information on the status of multilateral conventions and instruments in respect of which the International Maritime Organization or its Secretary-General performs depositary or other functions."
Organization of American States
The OAS website has a page titled Inter-American Treaties. For each agreement there is a table of ratifications and signatories that also has notes as to reservations, understandings and declarations that were entered.
United Nations Educational, Scientific and Cultural Organization
For each of the international agreements adopted under the auspices of UNESCO there is a link to an alphabetical listing of state parties with relevant dates and also a link to the text of reservations, understandings and declarations that were entered.
World Intellectual Property Organization
The WIPO website has a page titled WIPO-Administered Treaties. For each of the 26 international agreements listed there is a link to an alphabetical list of contracting parties.
Under article 32 of the Vienna Convention on the Law of Treaties, when interpreting an international agreement, recourse may be had to supplementary means of interpretation, including the drafting history (travaux préparatoires), to confirm the meaning of the agreement, or when the meaning is ambiguous or obscure, or to avoid a result that is manifestly absurd or unreasonable. Locating the drafting history of a multilateral agreement can be difficult. Two solutions are mentioned here.
Collected Travaux Préparatoires (Yale Law Library)
This webpage provides links and citations to the drafting history of a good number of multilateral agreements.
This article at the Globalex website presents five models of the publication of travaux préparatoires with references.
(This section derives from Georgetown Law Library's Treaty Research Guide.)
National Treaty Collections
Argentina Digital Library of Treaties (Spanish only)
Belgium Treaties Database
France Traités et Accords de la France (French only)
Indonesia International Treaty Search (searchable in English)
Israel Data Base of Treaties (searchable in English)
Italy Archive of International Treaties Online (Italian only)
Mexico Treaties Search (Spanish only)
Netherlands Treaty Database (searchable in English)
Norway's Treaties (Norwegian only)
Poland Internet Treaty Database (searchable in English)
South Korea Treaties (Korean only)
Sweden's International Agreements (Swedish only)
United Kingdom Treaties Online
Regional Treaty Collections
African Union -- OAU/AU Treaties, Conventions, Protocols & Charters
European Union Treaties in the EUR-Lex Database
Organization of American States (OAS) -- Multilateral Treaties & Bilateral Agreements
Treaties by Subject
Culture, Cultural Heritage & Education
Conventions & Legal Instruments (UNESCO)
Environment
Health
International and Regional Instruments -- Global Health & Human Rights Database
Human Rights
The Core International Human Rights Instruments and their Monitoring Bodies (Office of the U.N. High Commissioner for Human Rights)
Human Rights Treaties and Other Instruments (University of Minnesota Human Rights Library)
Intellectual Property
WIPO-Administered Treaties (World Intellectual Property Organization)
International Humanitarian Law
Treaties, States Parties and Commentaries (International Committee of the Red Cross)
International Investment Law
International Investment Agreements Navigator (U.N. Conference on Trade and Development)
International Trade & Commerce
UNCITRAL Texts and Status (United Nations Commission on International Trade Law)
WTO Legal Texts and Pre-WTO Legal Texts (World Trade Organization)
Labor & Employment
NORMLEX Conventions (International Labour Organization)
Outer Space
Space Law Treaties and Principles (U.N. Office for Outer Space Affairs)
Private International Law
Conventions, Protocols and Principles (Hague Conference on Private International Law)
UNIDROIT Instruments (International Institute for the Unification of Private Law)