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Foreign & International Law

This subject guide provides selected resources on foreign law and international law.

International Law

International law applies to relationships between states. This includes the law created by treaties and other agreements between states as well as the law created by long-established customs between states and what have become basic principles of international law. For more on the concept of international law read the International Law entry from Black's Law Dictionary, and to introduce you to the subject on international law read the nutshell on Public International Law included below.

After reading this guide do you still have questions about International Law research?

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Research Guides

Sources of International Law

Because of the nature of international law answering this question requires some explanation. See the reading linked above. However, Article 38 of the Statute of the International Court of Justices lists the following sources of international law, and it is an authoritative source.

  1. Conventions (I.E. different kinds of international agreements. E.G. a treaty.)
  2. Customary international law
  3. General Principles of International Law
  4. Judicial decisions
  5. Writings of international legal scholars

How does this apply to the United States?

The United States has the following classifications of international agreements. All of these falls into the first item from the above list, and each binds the United States in a different way. See the reading linked above.


  • Advice & consent from 2/3 of Senate
  • Ratification by President

Congressional-Executive Agreement

  • Approval of simple majority of both houses of Congress
  • Approval of the President

Sole Executive Agreement

  • International agreement executed solely by the President

Citations to U.S. Treaties

Determine if a treaty signed by the U.S. exists, and get the information to help you locate a copy.

Checking Treaty Status

Determine if a treaty binds the United States now.

Finding U.S. Treaties

Locate a copy of a treaty.



Unofficial sources

Treaty Background Research

The value of background research on treaties is analogous to the value of legislative history research on statutes, and it is similarly controversial. See the reading linked above.

Legislative History

  • The Congressional Record contains debates about some treaties.
    • Also available below at and through HeinOnline below.

Travaux Preparatoires

Finding Judicial Opinions

Judicial opinions in the United States interpret and rule on the constitutionality of statutes. Similarly, judicial opinions can be used to interpret international law. However, the concept of precedent or stare decisis is tied to a common law jurisdiction like the Unites States. Judicial opinions dealing with constitutional law matters work differently. See the reading linked above.

Digests on international law let you find judicial opinions on a topic relevant to your research.

Foreign & International Law Resources

eResources on Foreign & International Law

Below is a list of every electronic resource on the list of selected research databases that is tagged as having to do with foreign & International law.

International Law Resources

Bloomberg Law, Lexis, & Westlaw


This guide was created in February 2021 from the "International, Foreign & Comparative Legal Research" guide that had been created by Bobbi Weaver in September 2010. The older guide is no longer updated, but it remains available at the above link for its wider scope and its inclusion of resources available at other libraries in San Diego.

This guide was last updated by Bobbi Weaver and Robert O'Leary in February 2021.