Armed conflict and international law involves researching two bodies of law:
Armed conflict may also involve researching other areas of law: refugee law, human rights, migration, peaceful settlement of disputes, diplomatic relations, environmental law, and more.
The following books, in addition to more general encyclopedias about public international law, offer good overviews and background information about military and humanitarian law.
The Oxford Handbook of International Law in Armed Conflict by 
The Oxford International Encyclopedia of Peace by 
The Oxford Handbook of the International Law of Global Security by 
The Handbook of International Humanitarian Law by Peace Palace Library - A good way to keep up new publications, news and blogs featured on the Peace Palace Library website, is to use the Peace Palace Library’s Search Website box at the center of the home page. For more books and articles, click on Catalogue at the top of the home page. Simply select “international humanitarian law” and the database will run a search for all items in the Peace Palace catalog with this tag. At the bottom of the page is a list of research guides.
The International Committee of the Red Cross's (ICRC) International Humanitarian Law (IHL) Databases provide international agreement texts; customary law, and national implementing legislation:
Sources of Treaty and Treaty Preparatory Materials
Treaties, States Parties, and Commentaries: access to the Geneva conventions plus other treaties and documents, includes current status and ratification information. This database also includes Commentaries for the on the four Geneva Conventions and their two Additional Protocols of 1977. Note: the Commentaries are also available in print (4 vols.) in the Law Library and in PDF at the Library of Congress website.
Geneva Convention preparatory documents (ICRC Library).
Geneva Conventions Materials, Library of Congress, Military Legal Resources, Articles & Essays includes a collection of ICRC and US Government materials related to the conventions.
MN Human Rights Library: Law of Armed Conflict, collection (with citations) to many international instruments.
Laws of War, Yale's Avalon Project, provides access to a historical collection of instruments and documents.
Other Sources of Multilateral Treaties: For other sources and information about international agreements, consult the Treaty Basics pages of Basic & Background Resources -- Foreign and International Law.
Sources of National Implementing Legislation
National Practice: the ICRC database includes the texts of national implementing legislation adopted by States. Such measures may take a variety of forms, including constitutional provisions, specific laws (e.g. Geneva Conventions Acts), parts of more general laws (e.g. criminal codes), regulations and decrees. Relevant decisions of national courts are also included when available.
International Review of the Red Cross, a biannual journal on international humanitarian law. A thematic update on national implementation of international humanitarian law called What's New in Law and Case Law Around the World was produced from 2014–2019.
International Crimes Database, a fairly comprehensive database on international crimes adjudicated by national, as well as international and internationalized courts.
Sources of Customary Humanitarian Law
Customary International Humanitarian Law, the online updated coverage of the Study on customary international humanitarian law, conducted by the International Committee of the Red Cross (ICRC) and published by Cambridge University Press in 2005.
For other sources of national law, see the research guide, Basic & Background Sources of Foreign & International Law.
There is no one database that provides access to all cases from international courts and tribunals.
Free, public tribunal website databases:
International Court of Justice
World Court Digest, a compendium of the jurisdiction of the International Court of Justice.
International Criminal Court for the Former Yugoslavia
Topical Digest of Case Law (Human Rights Watch)
International Criminal Tribunal for Rwanda (legacy site after ICTR closed Dec. 31, 2015)
Digest of the Case Law (Human Rights Watch)
Special Court for Sierra Leone and Residual Special Court for Sierra Leone ("The Residual Special Court for Sierra Leone was established by an agreement between the United Nations and the Government of Sierra Leone to oversee the continuing legal obligations of the Special Court for Sierra Leone after its closure in 2013. These include witness protection, supervision of prison sentences, and management of the SCSL archives. This website includes and significantly expands the information contained in the original SCSL website.")
Extraordinary Chambers in the Courts of Cambodia (select English)
International Crimes Database, a fairly comprehensive database on international crimes adjudicated by national, as well as international and internationalized courts.
International Law Reports (UCB only), reprints, in English, selected decisions from the highest national courts as well as international courts and tribunals. To access, choose "Advanced Search" in left-side menu, and then select the "Cases" option in the top bar. Narrow your search to the specific database from choices on the right. Also available in print.
Oxford Reports on International Law (UCB only), provides access to jurisprudence from the African Commission, the European Court of Human Rights, and several UN Human Rights Treaty Bodies.
WorldLII, International Courts & Tribunals Project, access to cases from selected international courts and tribunals.
International Courts Data, blog and portal for an empirical study of international courts, includes datasets.
Websites:
ICRC Website, provides access to many resources including treaties, international documents, articles, reports and more.
UN Office for the Coordination of Humanitarian Affairs, provides links to news, reports and information on current areas in need.
The Center for Law and Military Operations (CLAMO), a selection of CLAMO publications available in PDF, including operational law handbooks.
Program on Humanitarian Policy and Conflict Research, the collection of publications includes an Occasional Paper Series, journal articles, book chapters, conference reports, policy briefs, and more. Many of these items are available in PDF. Also includes many featured projects: "IHL in Air and Missile Warfare," "Humanitarian Law and Policy Forum," and more.
ReliefWeb, this is an incredible resource containing news, reports, documents, maps, and other information. The advanced search allows the research to search by keyword and limit to a specific type of document (news, agreement, analysis) or by emergency. This is a good way to locate documents from other organizations.
IRIN: Humanitarian News and Analysis.
Rule of Law in Armed Conflicts Project (RULAC), access to law and information on countries and issues. Contains a Legal Developments Archive.
Blogs and Podcasts:
Armed Groups and International Law.
Intercross (ICRC's blog).
Robert Chesney's National Security Law Listserv.
The Morning Brief, news round-up about security, law and policy (Fordham Law School, Center on National Security).
Oxford Institute for Ethics, Blogposts
War in Context [Blog].
Other Research Guides
Globalex, research guides on international, foreign and comparative law topics.
Harvard Law Library, International Humanitarian Law research guide.
Peace Palace Library, Research Guide: International Humanitarian Law, includes citations to books and articles
One of the best ways to locate articles is to use legal journal indexes. Try these indexes:
Selected Journals:
African Yearbook on International Humanitarian Law (Juta, 2006-)
Global Responsibility to Protect (Brill, 2009-).
Ethics & International Affairs (Carnegie Council on Ethics and International Affairs, 1987-).
International Review of the Red Cross (ICRC, 1961-).
Journal of Conflict & Security Law (previous title, Journal of Armed Conflict Law) (Oxford University Press, 2000-).
Journal of International Criminal Justice (Oxford University Press, 2003-).
Journal of International Humanitarian Legal Studies (Martinus Nijhoff, 2010-).
Journal of International Peacekeeping (Martinus Nijhoff, 2009-).
Journal on the Use of Force and International Law (Routledge, 2014-). Contains a "Digest of State Practice" in each issue.
Philosophy & Public Affairs (Princeton, 1971-).
Revue Humanitaire (Médecins du Monde, 2000-).
Yearbook of International Humanitarian Law (Cambridge University Press, 1998-).
To identify books in our collection, search LawCat using keywords. Search the catalog by title, keyword or subject.
ANDREA BIANCHI, INTERNATIONAL HUMANITARIAN LAW AND TERRORISM (Hart, 2011).
ANTHONY CULLEN, THE CONCEPT OF NON-INTERNATIONAL ARMED CONFLICT IN INTERNATIONAL HUMANITARIAN LAW (Cambridge University Press, 2010).
APPLYING INTERNATIONAL HUMANITARIAN LAW IN JUDICIAL AND QUASI-JUDICIAL BODIES: INTERNATIONAL AND DOMESTIC ASPECTS (Springer, 2014). Also available electronically
ARMED CONFLICTS AND THE LAW (Intersentia, 2016).
BEYOND RESPONSIBILITY TO PROTECT: GENERATING CHANGE IN INTERNATIONAL LAW (Intersentia, 2016).
CUSTOMARY INTERNATIONAL HUMANITARIAN LAW (JEAN-MARIE HENCKAERTS AND LOUISE DOSWALK-BECK eds.) (Cambridge; New York: Cambridge University Press, 2005). See also the ICRC database
DEPARTMENT OF DEFENSE, LAW OF WAR MANUAL (June 2015, updated July 2023).
INTERNATIONAL HUMANITARIAN LAW SERIES (Martinus Nijhoff Publishers). This series of monographs and edited volumes aims to promote scholarly analysis and discussion of both the theory and practice of the international legal regulation of armed conflict.
INTERNATIONAL LAW AND THE CLASSIFICATION OF CONFLICTS (Oxford University Press, 2012).
CHRISTOPHER KUTZ, ON WAR AND DEMOCRACY (Princeton; Oxford: Princeton University Press, 2016).
JACKSON MAOGOTO, TECHNOLOGY AND THE LAW ON THE USE OF FORCE : NEW SECURITY CHALLENGES IN THE TWENTY-FIRST CENTURY (ROUTLEDGE, 2015).
AMREI MULLER, THE RELATIONSHIP BETWEEN ECONOMIC, SOCIAL AND CULTURAL RIGHTS AND INTERNATIONAL HUMANITARIAN LAW (Nijhoff, 2013).
NEW TECHNOLOGIES AND THE LAW OF ARMED CONFLICT (Springer, 2014). Also available electronically
OXFORD HANDBOOK OF INTERNATIONAL LAW OF ARMED CONFLICT (OXFORD, 2014). Also available electronically.
MICHAEL LEWIS, ET AL., THE WAR ON TERROR AND THE LAWS OF WAR: A MILITARY PERSPECTIVE, 2d ed. (Oxford University Press, 2015).
GARY SOLIS, THE LAW OF ARMED CONFLICT: INTERNATIONAL HUMANITARIAN LAW IN WAR, 2d ed. (Cambridge University Press, 2016).
TALLINN MANUAL ON THE INTERNATIONAL LAW APPLICABLE TO CYBER WARFARE (Cambridge University Press, 2013). Also available on the CCDCOE website
U.S. MILITARY OPERATIONS: LAW, POLICY AND PRACTICE (Oxford University Press, 2016).
MICHAEL WALZER, JUST AND UNJUST WARS: A MORAL ARGUMENT WITH HISTORICAL ILLUSTRATIONS, 5th ed. (2015).