Public international law governs the conduct of states and international organisations, and the relations between them. Areas of public international law include air law, diplomatic relations, the law of armed conflict, environmental law and trade law.
The Statute of the International Court of Justice, article 38(1), is often used to define the sources of public international law. It lists the following sources: treaties; international custom (hence "customary international law"); generally recognised principles of law; judicial decisions; and the teachings of publicists, that is, leading scholars. Judicial decisions and the teachings of publicists are classed as secondary sources (art. 31(1) (d)).
IALS Library has a large public international law collection, comprising several treaty series; numerous international law reports; hundreds of yearbooks and journals, print and electronic; and thousands of monographs. A large area of the second floor reading room is devoted to international law, and additional holdings are kept in the basement Reserve and Offsite Store. IALS also subscribes to many online databases with substantial international law content.
A treaty is a written agreement between two or more states or international organisations. It does not necessarily have the word “treaty” in its title: it could call itself a "convention", "agreement", or something else.
Some common terms are listed below; for others, see the UN Treaty Reference Guide.
The United Nations Treaty Series (UNTS, 1946 - )
This is the leading publication for multilateral and bilateral treaties. All treaties entered into by UN member states have to be registered with the UN and published in the UNTS. However, some treaties are missing from the series and publication of new treaties is slow; for treaties not in the UNTS, use a treaty index to find other sources.
The entire UNTS is available free on the UN Treaty Collection website, with details of signatures, ratifications and so on. It is also in Hein Online's UN Law Collection. IALS has the bound set up to vol. 2174 (2002), including cumulative indexes; they are kept in the Offsite Store.
The Oxford Standard for the Citation of Legal Authorities says the UNTS should be cited in preference to other treaty sources (OSCOLA 2006, Citing International Law Sources, p.25).
Multilateral Treaties Deposited with the Secretary General (MTDSG, 1949 - )
This UN publication records signatures, ratifications and other treaty actions, but only covers the 500 or so treaties officially deposited with the Secretary General, a very small proportion of the treaties in the UNTS. It includes details of some treaties pre-dating the UN.
MTDSG is on the UN Treaty Collection website, under Status of Treaties, and is updated here on an ongoing basis. The annual print edition is held at IALS from 1949 to 2006 (the title varies- see Catalogue). HeinOnline has the latest annual edition.
League of Nations Treaty Series (LNTS, 1920 -1946)
The LNTS contains treaties made by member states of the League of Nations, 1920 to 1945, with indexes. It is in the UN Treaty Collection and on HeinOnline. IALS has the entire printed series, in the Offsite Store. The formal title of the LNTS is Treaty series and international engagements registered with the Secretariat of the League of Nations.
This series is produced every two months by the American Society of International Law (ASIL). It used to publish important new treaties, but now that most major treaties are available on the internet, it gives the URL instead of reproducing the text. The treaties covered by ILM are often accompanied by introductory notes.
IALS has the printed volumes of ILM and it is also on Lexis Library (whole series), Westlaw International (via Westlaw UK, 1980 onwards) and HeinOnline (1962 to pre-current volume). These databases may be accessed via the Electronic Law Library.
Council of Europe (CoE)
Council of Europe treaties are published in the European Treaty Series (ETS, 1949-2003), renamed Council of Europe Treaty Series (CETS) from 2004. IALS holds the entire series. All CoE treaties are also on its website, together with explanatory reports and status information (ratifications and so on).
European Union (EU)
The EU uses the term "treaty" specifically for its fundamental treaties, such as the Treaty on the Functioning of the European Union. For other international instruments, it uses the term "agreement", for example, the Agreement between the European Community and the Government of Japan concerning cooperation on anti-competitive activities.
Both treaties and international agreements appear in the Official Journal of the European Union (formerly ...of the European Communities), which is held at IALS. They are also on the free EUR-Lex website, as well as on the subscription databases Lexis, Westlaw and Justis (see IALS Electronic Law Library).
Status information for EU treaties and international agreements is available from the Council of the EU’s website, under Agreements. The European Commission has a database of international agreements concluded by the EU, including summaries, citations and other information, together with links to the full text.
Organization of American States (OAS)
OAS treaties appear in its Treaty Series, which is held at IALS from 1970 to 1985 only. All OAS treaties are on its website, with status information.
Many countries publish the treaties to which they are a party in their own official series; some also make them available on the internet. This research guide covers five jurisdictions only (see below); sources for other jurisdictions may be available via WorldLII, or the Eagle-I web portal.
Treaties in force for Australia are officially published in the Australian Treaty Series (ATS, 1901- ). The whole series is on AustLII, together with Australian Treaties Not Yet in Force (ATNIF). Status information, 1990 onwards, is available from the Department of Foreign Affairs and Trade.France
France publishes its treaties in the Journal officiel de la République française (JORF). IALS does not hold the printed JORF, but it is on LexisNexis JurisClasseur from 1990 onwards and free on the internet from 2004 onwards.
French treaties are also available on the website of the Foreign Ministry, with status information, in a database going back to the sixteenth century, at least.
Germany publishes its treaties in part II ('Teil II') of the Bundesgesetzblatt (BGBl), formerly the Reichs-Gesetzblatt (RGBl).The BGBl is available free on the internet from 1951 onwards. IALS has the printed RGBl from 1899 to 1945 (plus incomplete holdings of earlier volumes) and the BGBl on microfiche from 1949 to 1980.
Treaties in force for the UK appear in the UK Treaty Series (UKTS, 1892 - ). UKTS is compiled by the Foreign and Commonwealth Office (FCO), with indexes, and published by The Stationery Office. Before they come into force for the UK, bilateral treaties are published in the Country series of command papers, mulilaterals in the Miscellaneous series and EC/EU treaties in the European Community/Union series.
IALS has the UKTS, from 1946 onwards, but does not hold the other series. The FCO website has UK treaties from 1892 onwards, whether in force or not: for treaties up to 1998, click on UK Treaties Online and for treaties from 1999 onwards, click on Treaty Command Papers.
Status information for UK treaties is published biannually, in the FCO’s Supplementary List: Treaty Ratifications, Accessions, Withdrawals, Etc and Second Supplementary List…, which are types of command paper. The FCO website has ten years' worth of these Lists. Status information for treaties deposited with the UK is available from the Depositary page of the FCO site (as well as in the Supplementary Lists). Status information can also be obtained by calling the FCO Treaty Section.
British and Foreign State Papers (BFSP) has treaties from 1812 to 1968, plus treaties concluded before 1812 which were still in force at the time of publication. The series was compiled by the Foreign Office and published from about 1815 up to 1970s, with indexes. IALS's printed set is incomplete, but the whole series is in HeinOnline’s World Constitutions Illustrated module.
For old treaties not in BFSP, see Parry and Hopkins, An Index of British Treaties (below).
International instruments concluded by the US are categorised either as “treaties” or as “international agreements”, depending on the type of procedure used to approve them.
US treaties and international agreements are first published in the Treaties and Other International Acts Series (TIAS), then cumulated into United States Treaties and Other International Agreements (UST, 1950 - ). Before 1950, they were published in Statutes at Large (Stat.). IALS has UST and Statutes at Large, but does not hold TIAS.
Publication of UST is many years in arrears: the last issue to come out was vol. 35(6), covering treaties from 1983-84. The State Department website currently warns that there are problems with the funding of the series.
Online sources of US treaties and agreements
Status information and indexes
Treaties and agreements in force for the US are listed in the annual title Treaties in Force, with details of signatories, parties, the date in force, amendments and so on. The current edition is on the State Department website; current and previous editions are on Lexis, Westlaw International and Hein Online; IALS has the printed editions from 1964 onwards.
See also Kavass’s Guide to the United States Treaties in Force and the United States Treaty Index (details below).
Selected subject-based collections are listed below (for other subjects, see EISIL):-
Clive Parry's Consolidated Treaty Series (CTS, or Consol.T.S.) is the main source of treaties from 1648 to 1920. IALS has the whole series, more than two hundred volumes. Other historical collections include: -
• Hertslet's commercial treaties: treaties 1354 -1921, with indexes; held at IALS.
• Martens, Recueil de traités…(treaties 1761-1808); Nouveau recueil de traités... (1808-1839); Nouveaux supplémens au Recueil de traités...(supplement to the above titles, 1761-1839); Nouveau recueil général de traités.... (1840-1841 only in IALS, but further volumes were published). In various languages, not just French.
• The Avalon Project, at Yale Law School, provides key treaties dating from the ninth century onwards.
Treaty indexes and bibliographies have the classmark BS40 at IALS Library. Key works are kept behind the Enquiry Desk for ready reference (see Library Catalogue). The following are some of the most important indexes available at IALS (or on the internet):-
Customary international law develops when the general practice of states comes to be accepted as a legal obligation. There is a useful introduction to the concept of state practice in M. Wood, 'State Practice', in R. Wolfrum (ed.), The Max Planck Encyclopedia of Public International Law (printed and online versions available at IALS).
Researchers may find evidence of state practice in diplomatic correspondence, legislation, legal opinions, national and international court decisions, treaties, parliamentary debates and elsewhere. Some of these materials are not published, but others are found in yearbooks, journals and digests, in International Legal Materials, or in national collections of international law cases.
The following bibliographies list sources of state practice:
Yearbooks and digests outline state practice in international law under systematic subject headings. They reproduce extracts from state practice materials, summarise national court decisions on international points and give details of treaty actions.
Most yearbooks are national in scope, but some are regional, for example the African Yearbook of International Law and the Asian Yearbook of International Law. Selected yearbooks and digests are detailed below (Australia, France, Germany, UK and US). For other parts of the world, see bibliographies, or search the Catalogue; IALS has a large collection of yearbooks.
Many international law journals cover state practice, for example: the American Journal of International Law, the Chinese Journal of International Law and the Heidelberg Journal of International Law (the practice section of the latter is on the internet, 1993-2005). For details of other journals with state practice materials, see bibliographies.
A few surveys have been produced covering state practice in particular areas of law. They include the following:
Information about a state's current foreign policy practice may be found on its foreign ministry website - see WorldLII for links. Websites for state practice are also listed in Gaebler and Smolka-Day (ed.s), Sources of State Practice in International Law.
Judicial decisions are a secondary source of international law, according to article 31(1) (d) of the Statute of the International Court of Justice.
The broadest collections of international law decisions are found in the International Law Reports, Oxford Reports on International Law, WorldLII and International Legal Materials, as detailed below.
International Law Reports (ILR)
ILR is the leading reporter of international law decisions in English. It publishes the decisions of international courts and arbitral tribunals and the decisions of municipal courts in matters of international law, around 10,000 decisions, from 1919 to the present day. ILR began in the 1920s, as the Annual Digest of Public International Law Cases (cited as ADIL, AD, Ann.Dig or Annual Digest). Originally published by Longman and later by Butterworths, it is now a Cambridge University Press title.
IALS Library has the whole printed ILR series, more than 140 volumes. There is an online version produced by Justis Publishing, but IALS does not currently susbcribe to this.
Oxford Reports on International Law (ORIL)
ORIL is an Oxford University Press subscription database (see Electronic Law Library). It has five modules, comprising more than 4,000 decisions in total:
- International Law in Domestic Courts: selected municipal decisions in the field of international law; judgments in the vernacular, with key passages translated into English where necessary; includes scholarly commentary. Most of the decisions date from 2000 onwards.
- International Courts of General Jurisdiction: cases from the ICJ, Permanent Court of International Justice, International Tribunal for the Law of the Sea and Permanent Court of Arbitration, 1902 onwards.
- International Criminal Law: decisions of the International Criminal Court, the Tribunals for Rwanda and the former Yugoslavia, the Extraordinary Chambers in the Courts of Cambodia, the Special Court for Sierra Leone and the Nuremberg International Military Tribunal. Most decisions date from the 1990s onwards.
- International Human Rights Law: cases from the African Commission on Human and Peoples Rights, Inter-American Court of Human Rights, European Court of Human Rights and elsewhere, 1961 onwards.
- International Investment Claims: all publicly available awards and decisions in international investment arbitration cases, together with enforcement or review decisions from national courts. Includes cases from ICSID, the ICC International Court of Arbitration and many other arbitral bodies, 1990 onwards.
WorldLII International Courts and Tribunals Collection
The WorldLII website brings together cases from more than 30 international courts and tribunals, plus UN committees, in a searchable database. Generally speaking, the content starts in the 1980s, the 1990s, or the 21st century; however, for some courts it goes back much further. The content is not always current - the court's own website may be more up-to-date.
International Legal Materials (ILM, 1962 -)
ILM publishes a selection of international law decisions, with introductory notes. IALS has the whole printed series. ILM is also on Lexis Library (whole series), Westlaw International (via Westlaw UK, 1980 onwards) and HeinOnline (up to pre-current volume); all these databases are available via the IALS Electronic Law Library.
The decisions of municipal (national) courts in matters of international law are available in various collections. IALS Library's holdings include the following:-
The International Law Reports and ORIL's International Law in Domestic Courts cover municipal decisions on international law from many different jurisdictions.
Almost every international court and tribunal has its own website, on which its decisions are available. Many also produce their own series of law reports in printed format. For courts and tribunals not covered below, see General Sources, or the court/tribunal's website.
Further information about international judicial bodies is available in Mackenzie et al, Manual on international courts and tribunals (2nd ed., OUP, 2010) and from the website of the Project on International Courts and Tribunals (PICT).
The International Court of Justice (ICJ) was inaugurated in 1946. It publishes its decisions and related documents in two series: Reports of Judgments, Advisory Opinions and Orders and Pleadings, Oral Arguments and Documents. IALS has both series; they are also available on the ICJ website, HeinOnline, Lexis Library and Westlaw International. ICJ decisions may also be found in general sources such as ILR and ORIL.
There is a detailed guide to ICJ-related research on Cornell University's website.
The Permanent Court of International Justice
The Permanent Court of International Justice (PCIJ) was the forerunner of the ICJ. It operated from 1922 to1940 and was formally dissolved in 1946. PCIJ decisions and related documents were published by the Court in the following series:
Publications of the Permanent Court of International Justice. Series A, Collection of Judgements
Publications of the Permanent Court of International Justice. Series B, Collection of Advisory Opinions
Publications of the Permanent Court of International Justice. Series A./B., Judgments
Permanent Court of International Justice. Series C, Pleadings, Oral Statements and Documents
The International Criminal Court (ICC) was established in 2002. It has made many procedural decisions in ongoing cases and delivered its first judgment in March 2012. The ICC website provides transcripts and other court documents, for both ongoing and concluded cases. WorldLII has ICC procedural decisions and transcripts up to 2010.
Summaries of selected ICC decisions appear in The Annotated Digest of the International Criminal Court, edited by Cyril Laucci (Martinus Nijhoff, 2007- ). IALS subscribes to this series.
Outlines of ongoing proceedings are included in the ICC's annual reports to the UN, entitled Report of the International Criminal Court: Note by the Secretary-General. These reports are available on the ICC website and in the UN Official Document System.
See also the general sources outlined above.
The international, or internationalised, criminal tribunals provide their decisions and other documents on their websites:
See also: Annotated leading cases of international criminal tribunals (held at IALS); and general sources, above.
The European Court of Human Rights was set up by the Council of Europe to hear cases involving alleged breaches of the European Convention on Human Rights. It delivered its first judgment in 1960. It is not to be confused with the European Court of Justice, which is an EU institution - see below. There used to be a European Commission of Human Rights as well, but the Commission was merged into the Court in 1998.
The official website, HUDOC, provides all the Commission's reports and decisions and almost all the Court's decisions.
The Court's decisions and other documents appear in these official series, all held at IALS:-
The Commission's decisions were officially published in the following series, both held at IALS:-
See also the general sources outlined above.
The Court of Justice is the European Union's original court, established in 1952. It is often known as the European Court of Justice, or ECJ. Since the late 1980s, it has been assisted by the General Court (formerly the Court of First Instance).
Decisions are officially published in Reports of Cases before the Court of Justice and the General Court, commonly know as the 'European Court Reports', and cited as ECR. New decisions are slow to appear in the ECR; online sources are more current: the official Curia and EUR-Lex websites and the subscription databases Lexis, Westlaw UK and Justis CELEX. See also the general sources outlined above.
For further information about EU research, see IALS Library's European Union research guide.
The Inter-American Court of Human Rights was set up by the Organization of American States in 1979, under the American Convention on Human Rights. The Inter-American Commission on Human Rights was established in 1959. IALS does not hold their official publications, but extracts from leading cases may be found in Burgorgue-Larsen and Úbeda de Torres, The Inter-American Court of Human Rights: case law and commentary; and Human Rights: the Inter-American System, Thomas Buergenthal and Robert E. Norris, ed.s (Oceana, 1982-1993; has a useful case index). Cases are also available online - see below.
The Court's decisions and related documents are officially published in:
The Commission's decisions are officially published in the Annual Report of the Inter-American Commission on Human Rights. Indexes to these decisions have been published in 10 Am.U.J.Int'l L.& Pol. 19 and 16 Am. U. Int'l L. Rev. 353 (available on HeinOnline), and in the Repertorio de Jurisprudencia, mentioned below.
Arbitration falls into the category of public international law when it involves the resolution of disputes between states. Commercial arbitral awards are more accurately categorised as transnational law, rather than public international law; for information about researching international commercial arbitration, see ASIL's Electronic Resource Guide.
ICSID Reports: Reports of cases decided under the Convention on the Settlement of Investment Disputes...and related decisions... (Grotius, 1993 - ). Has cases dating from 1975 onwards; held at IALS. ICSID cases are also on its website.
Iran-United States Claims Tribunal Reports (Grotius, 1983 - ): all the decisions of the Tribunal since it was established in 1981. Printed series held at IALS; also on Westlaw International (via Westlaw UK).
Reports of International Arbitral Awards (RIAA; United Nations, c.1948 - ): arbitrations between states from the 1920s onwards. IALS has the printed series and it is also available on the UN website and HeinOnline.
The International Human Rights Law module of Oxford Reports on International Law has decisions from all the major human rights bodies, including UN committees. See also European Court of Human Rights and Inter-American Court of Human Rights, above.
The International Tribunal for the Law of the Sea (ITLOS) provides all its cases on its website and publishes them in the printed series, Reports of judgments, advisory opinions, and orders (IALS Library's holdings are incomplete). See also ORIL and ILR.
WTO decisions are available on its website and in the printed series Dispute Settlement Reports (held at IALS). They are also on the subscription databases Lexis Library, Westlaw International and WorldTradeLaw.net. Commentary on WTO decisions is available on the subscription database WordTradeLaw.net, together with the decisions themselves.
The teachings of leading scholars in the field of public international law ('publicists') can be cited as evidence of international law. These teachings may be found in treatises, journals, the Max Planck Encyclopedia of Public International Law and the publications of the International Law Commission. They are even available in video format, in the UN Lecture Series.
The selection of particular authorities is a subjective process. In the UK, established treatises include Jennings, R., Oppenheim's International Law (9th ed., OUP, 1992); Brownlie, I., Principles of Public International Law (7th ed., OUP, 2008); and McNair, A., Law of treaties (Clarendon Press,1961). Further information about books, journals and the Max Planck Encyclopedia is given below.
IALS has a very large collection of books on public international law: see Library Catalogue. Their main location is the second floor reading room, but some key texts are kept in the Short Loan Collection on the fourth floor and older works are in the basement Reserve. The collection comprises classic treatises, introductory textbooks and compilations of cases and materials.
General titles include the following:
Scholarly articles on international law topics are published in both journals and yearbooks. IALS subscribes to a very large number of these series; to find them on the Library Catalogue, search by Subject Heading "international law--periodicals".
The following are a selection of leading international law journals, all held at IALS:
The Library holds many national and regional yearbooks of international law, for example, the British Yearbook of International Law, the Canadian Yearbook of International Law and the African Yearbook of International Law.
The Max Planck Encyclopedia of Public International Law (MPEPIL) is edited by Rüdiger Wolfrum, Director of the Max Planck Institute for Comparative Public Law and International Law. The online version, a subscription service, was launched in 2008. A printed edition was published by Oxford University Press in 2012, in ten volumes. Both are available at IALS.
The Encyclopedia consists of articles by experts, embracing all aspects of public international law. It includes thirty-five "overview articles", providing an introduction to a broad area or fundamental concept of international law.
Listed below are a few key websites; links to more sites are provided in each section of this guide (see above).