A House with Two Rooms - The Advocates for Human Rights

II. Sources of International Law
Article 38 of the Statute of the International Court of Justice (ICJ) is generally regarded as a
complete statement of the sources of public international law. 1 Article 38 defines four primary
sources of public international law: 2
1. international conventions, whether general or particular, establishing
rules expressly recognized by the contesting states;
2. international custom, as evidence of a general practice accepted as
law;
3. the general principles of law recognized by civilized nations;
4. subject to the provisions of Article 59 [decisions of the Court
have no binding force except between the parties and in respect
of that particular case], judicial decisions and the teachings of the
most highly qualified publicists of the various nations, as subsidiary
means for the determination of rules of law. 3
1. International treaties, such as conventions, covenants, 4 protocols, 5 or pacts, are an important
source of international law. A treaty is generally a legally binding, written agreement concluded
between states or between the United Nations and a state. 6 At the international level, a state
establishes its consent to be bound through ratification, 7 acceptance or approval, 8 or accession. 9
Law-making treaties establish general norms for the future conduct of the parties, and the
obligations are basically the same for all parties. 10 States may sign treaties; however, until the treaty is
ratified, accepted, approved, or acceded to by domestic legislation, a state’s signature serves only as
an expression of the state’s intent to refrain from acts that would defeat the object and purpose of
the treaty. 11 Once a human rights treaty has entered into force, states have an obligation to strictly
perform their treaty obligations in good faith. 12 Examples of influential treaties in the human
rights area include the International Convention on Civil and Political Rights and the International
Convention on Economic, Social, and Cultural Rights. 13
2. Customary international law is derived from the actual conduct of states. The existence of a
custom is shown by two factors: (1) “settled practice,” and (2) “opinio juris.” 14 Settled practice may
be established even after relatively little time has passed so long as state practice is “both extensive
and virtually uniform in the sense of the provision invoked.” 15 Opinio juris may be established by
“evidence of a belief that [a certain] practice is rendered obligatory by the existence of a rule of law
requiring it.” 16 “It is thus beyond doubt that basic human rights obligations form part of customary
international law. . . . [T]he [ICJ] has expressly mentioned the crimes of genocide and aggression, as
well as the prohibition of racial discrimination, slavery, arbitrary detention and physical hardship as
forming part of a universally binding corpus of law, [but] it has not limited the scope of [customary
international] law to these elements.” 17
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