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International Legal Research: Customary International law

This guide will serve a beginning set of resources for those legal researchers who are searching in the field of international law. It will focus on finding treaties and other international agreements.

What is Customary International Law

Customary International Law

“Customary international law develops from the practice of States. To international lawyers ‘the practice of states’ means official governmental conduct reflected in a variety of acts, including official statements at international conferences and in diplomatic exchanges, formal instructions to diplomatic agents, national court decisions, legislative measures or other actions taken by governments to deal with matters of international concern.”  (Thomas Buergentahl & Sean D. Murphy, Public International Law in a Nutshell  22-23 (4th ed. 2007).

Evidence of a state’s practice is found in: (1) treaties; (2) decisions of national and international courts; (3) national legislation; (4) opinions of national legal advisors; (5) diplomatic correspondence; and (6) practice of international organizations.

Yearbooks

Yearbooks of States and Organizations

Yearbooks published by individual countries and by intergovernmental organizations provide a good way to assess information on state practice. They can note important legislation, case law and diplomatic practice involving international law.  Check library online catalogs and web sites for countries and IGOs. 

Includes prominent yearbooks from around the world in PDF format as well as a digest of U.S. practice in international law.

Sources of Customary International Law

Digests of Practice

Series of digests first published in 1877 act as encyclopedias of United States international law practice. The last published was Whiteman’s Digest of International Law covering 1940s-1960s. Available in the library’s print collection and in HeinOnline’s Foreign & International Law Resources Database.

Digests of U.S. Practice in International Law, 1973-

These digests supplement the earlier digests and cover smaller time periods.

Available in the library’s print collection and in HeinOnline’s Foreign & International Law Resources Database.

Foreign Relations of the United States  

Department of State’s official documentary historical record of major United States foreign policy decisions and significant diplomatic activity. Also available in library’s print collection.

Restatement (Third) of Foreign Relations Law of the United States, 1987.

Unofficial, but respected summary of United States law and practice in international law and foreign relations. Available on LexisNexis and Westlaw and in library’s print collection.

Judicial Decisions

                Includes decisions of courts as well as international tribunals.

International Court of Justice (ICJ), 1947-  http://www.icj-cij.org/homepage/index.php?lang=en

Source of text of decisions and activities of the most significant international court. Decisions also available on LexisNexis and Westlaw and in HeinOnline’s Foreign & International Law Resources Database.

International Criminal Court (ICC), 2002- http://www.icc-cpi.int/en_menus/icc/situations%20and%20cases/Pages/situations%20and%20cases.aspx

The International Criminal Court (ICC), governed by the Rome Statute, is the first permanent, treaty based, international criminal court established to help end impunity for the perpetrators of the most serious crimes of concern to the international community.  The ICC is an independent international organisation, and is not part of the United Nations system. Its seat is at The Hague in the Netherlands.

 

 

Judicial Decisions

                Includes decisions of courts as well as international tribunals.

International Court of Justice (ICJ), 1947-  http://www.icj-cij.org/homepage/index.php?lang=en

Source of text of decisions and activities of the most significant international court. Decisions also available on LexisNexis and Westlaw and in HeinOnline’s Foreign & International Law Resources Database.

International Criminal Court (ICC), 2002- http://www.icc-cpi.int/en_menus/icc/situations%20and%20cases/Pages/situations%20and%20cases.aspx

The International Criminal Court (ICC), governed by the Rome Statute, is the first permanent, treaty based, international criminal court established to help end impunity for the perpetrators of the most serious crimes of concern to the international community.  The ICC is an independent international organisation, and is not part of the United Nations system. Its seat is at The Hague in the Netherlands.