Michaelmas 2021 Sources of International Law Dr Andrew Sanger1 1. What are these lectures about? In these lectures, we will look at: . The sources of international law · Customary international law in depth · Whether there is a hierarchy of sources . Next time we will look at treaties in depth If you want a general chapter on the sources of international law to read, take a look at Roberts and Sivakumaran, 'The Theory and Reality of the Sources of International Law' in Evans (ed), International Law (5th edn, OUP, 2018) ch 4. 2. What are the sources of international law? 2.1 Development of our understanding of the sources of international law · 16th-18 centuries: Law of nations, with emphasis on law as a set of principles and customary practice, to an increase in treaties between states. Treaties were not key source of IL but normative Christian values. · Late 19th-20th century: greater use and range of treaties and the gradual development of (legal) dispute settlement mechanisms - this required a better understanding of the sources of law to be applied by these dispute settlement bodies. More states to engage in treaty making. Industrialisation = more trade and interconnection between states that need to be regulated. Shift to positivism rather than theology values, emphasis on treaty law. · Following World War I, the Permanent Court of Justice to the International Court of Justice was established-the first permanent standing court to deal with interstate disputes. The Advisory Committee of Jurists that drafted the statute of the Court were tasked with identifying the materials that the Court could use to resolve legal disputes. . Following World War II: The list of 'sources' in the Statute of the PCIJ becomes Article 38(1) of the Statute of the International Court of Justice, when the ICJ was established following World War II. Although the purpose of this provision was to provide a list of materials that the Court(s) could apply when resolving a dispute, it is now generally accepted as representing the sources of international law. Other international instruments/tribunals also refer to it: eg United Nations Convention on the Law of the Sea 1982, arts tt4(1), 83(1). 2.2 Article 38(1) of the Statute of the International Court of Justice 1 I am very grateful to Dr Federica Paddeu, whose handout on this topic was influential in shaping this one. Page 1 of 16
Michaelmas 2021 1. The Court, whose function is to decide in accordance with international law such disputes as are submitted to it, shall apply: a. international conventions, whether general or particular, establishing rules expressly recognized by the contesting states; b. international custom, as evidence of a general practice accepted as law; also local or regional custom between those in a geographical region. c. the general principles of law recognized by civilized nations; d. subject to the provisions of Article 59, judicial decisions and the teachings of the most highly qualified publicists of the various nations, as subsidiary means for the determination