Sources of International Law

Public International Law (PIL) is the body of rules governing relations between States and other international legal persons (international organisations, and to a limited extent individuals). Its rules are created mainly by consent of States, there is no world legislature, and enforcement rests largely on reciprocity, countermeasures and institutions such as the UN Security Council.

Schools of thought:

• Naturalists (Grotius, Vattel, Pufendorf): law derives from reason and natural law.

• Positivists (Bynkershoek, Oppenheim, Anzilotti): law derives from State consent (treaties and custom).

• Austin: international law is only ‘positive international morality’ since there is no sovereign command – the classic sceptic view. Hart answered that it is a primitive legal system lacking secondary rules.

• Grotius is the ‘Father of International Law’ (De Jure Belli ac Pacis, 1625).

Subjects of international law: States (primary), international organisations (Reparation for Injuries AO, 1949 – the UN has objective international personality), individuals (limited – human rights, ICC liability), and sui generis entities such as the ICRC, insurgents and national liberation movements.

States – Montevideo Convention 1933, Art 1: (a) permanent population, (b) defined territory, (c) government, (d) capacity to enter into relations with other States.

Article 38 is the most tested provision of the unit. It directs the Court to apply:

Points to remember:

• Article 38 does not create a formal hierarchy among (a), (b), (c), but in practice a treaty between the parties prevails as lex specialis.

• Article 59: the Court’s decision has no binding force except between the parties and in respect of that particular case – no formal stare decisis.

• The list is not exhaustive: unilateral acts, resolutions of international organisations and soft law are additional material.

• The Statute of the ICJ is annexed to the UN Charter; Article 92 of the Charter makes the ICJ the principal judicial organ.

Vienna Convention on the Law of Treaties (VCLT) 1969: adopted 23 May 1969, in force 27 January 1980. Applies to written treaties between States; not retroactive (Art 4). The 1986 Vienna Convention covers treaties involving international organisations. India is not a party to VCLT 1969 but accepts most of it as customary law.

Key provisions:

• Art 2(1)(a): ‘treaty’ = international agreement concluded between States in written form and governed by international law, whatever its particular designation.

• Art 11: consent to be bound may be expressed by signature, exchange of instruments, ratification, acceptance, approval or accession.

• Art 18: a State that has signed must refrain from acts that defeat the object and purpose of the treaty before entry into force.

• Arts 19–23: Reservations. Unilateral statement excluding or modifying legal effect of provisions. Not allowed if prohibited by the treaty or incompatible with its object and purpose. Reservations to the Genocide Convention AO (1951) introduced the ‘compatibility test’ replacing the old unanimity rule.

• Art 26: Pacta sunt servanda – every treaty in force is binding and must be performed in good faith.

• Art 27: internal law cannot be invoked as justification for failure to perform a treaty.

• Arts 31–33: Interpretation – good faith, ordinary meaning, context, object and purpose; supplementary means (travaux préparatoires) under Art 32.

• Art 46: a State cannot invoke violation of internal law on competence to conclude treaties unless the violation was manifest and concerned a rule of fundamental importance.

• Arts 46–53: Invalidity – error, fraud, corruption, coercion of a representative, coercion of a State by threat or use of force (Art 52), conflict with a peremptory norm (Art 53, jus cogens).

• Art 60: termination or suspension on material breach.

• Art 61: supervening impossibility of performance.

• Art 62: fundamental change of circumstances (rebus sic stantibus) – cannot be invoked for boundary treaties; narrowly applied in Gabčíkovo-Nagymaros (Hungary/Slovakia, 1997).

• Art 64: emergence of a new peremptory norm terminates conflicting treaties.

Other treaty concepts: bilateral/multilateral, law-making (traités-lois) vs contract treaties (traités-contrats), accession, protocol, optional protocol, depositary. Treaty-making in India: executive power under Arts 73 and 253; Parliament’s power to legislate to implement treaties (Art 253; Entry 14, List I); see Article 51(c) DPSP.

Elements (two-element test):

1. State practice (objective element) – extensive, representative, consistent and virtually uniform, including that of specially affected States.

2. Opinio juris sive necessitatis (subjective element) – belief that the practice is required by law.

Cases:

• Lotus (France v Turkey, PCIJ 1927): restrictions on sovereignty are not presumed; States have residual freedom unless a prohibitive rule exists; custom requires proof of opinio juris, not mere abstention.

• Asylum (Colombia v Peru, ICJ 1950): regional/local custom must be proved as constant and uniform usage accepted as law; Colombia failed to prove it.

• Right of Passage over Indian Territory (Portugal v India, ICJ 1960): bilateral local custom between two States is possible – Portugal’s right of passage for private persons and goods upheld, not for armed forces. (India-linked – high probability.)

• Anglo-Norwegian Fisheries (UK v Norway, 1951): persistent objector rule – a State that consistently objects while the custom is emerging is not bound; also straight baselines.

• North Sea Continental Shelf (Germany v Denmark/Netherlands, 1969): a treaty provision can generate custom if it is of fundamentally norm-creating character, but equidistance (Art 6, 1958 Convention) did not become custom; no minimum duration required, provided practice is extensive and virtually uniform.

• Nicaragua v USA (1986): non-use of force and non-intervention are customary even where treaty norms exist; treaty and custom co-exist; UNGA resolutions can evidence opinio juris.

• Jurisdictional Immunities of the State (Germany v Italy, 2012): State immunity as customary norm; Italian courts could not deny immunity for acts jure imperii even for war crimes.

• Nuclear Weapons AO (1996): UNGA resolutions may provide evidence of opinio juris but cannot by themselves create custom.

Instant/modern custom: Bin Cheng’s concept (outer space law). Persistent objector does not apply to jus cogens.

Principles common to major legal systems, applied to fill gaps (non liquet): good faith, res judicata, estoppel, equity, abuse of rights, no one may profit from own wrong, obligation to make reparation (Chorzów Factory, PCIJ 1928), limitation, due process.

• Judicial decisions: ICJ, PCIJ, arbitral awards, ITLOS, domestic courts (Pinochet, Filártiga).

• Teachings of publicists: ILC reports, Institut de Droit International, scholars.

• Unilateral acts: Nuclear Tests (Australia/NZ v France, 1974) – public unilateral declarations made with intent to be bound create legal obligations. Eastern Greenland (1933): Ihlen Declaration binding on Norway.

• Resolutions of UNGA: generally recommendatory (Arts 10–14 Charter); declarations like the UDHR (1948) have become evidence of custom. UNSC decisions under Chapter VII are binding (Art 25, Art 48).

• Soft law: guidelines, codes (e.g., Rio Declaration, Guiding Principles on IDPs).

• Jus cogens (peremptory norms): Art 53 VCLT – accepted by the international community of States as a whole as norms from which no derogation is permitted. Examples: prohibition of aggression, genocide, slavery, torture, racial discrimination, self-determination, core IHL. Erga omnes obligations – Barcelona Traction (Belgium v Spain, 1970, obiter); East Timor (Portugal v Australia, 1995).

• Dualism (Triepel, Anzilotti): two separate legal systems; treaties need transformation by legislation. Monism (Kelsen, Lauterpacht): one legal order; international law supreme. UK: custom is part of common law (incorporation); treaties need legislation (transformation). USA: treaties can be self-executing (Supremacy Clause).

• India: Art 51 (promotion of international peace and security, respect for international law and treaty obligations); Art 253; Art 73; Entry 14 List I. India follows a dualist approach for treaties – Parliament must legislate (Maganbhai Ishwarbhai Patel v UOI, 1969).

• Gramophone Company of India v Birendra Bahadur Pandey (1984): rules of customary international law not contrary to municipal law are deemed part of Indian law; courts should construe statutes to avoid conflict with international law.

• Vishaka v State of Rajasthan (1997): international conventions (CEDAW) read into Articles 14, 15, 19, 21 to fill a legislative vacuum, provided they do not contradict domestic law.

• Jolly Verghese v Bank of Cochin (1980), PUCL v UOI (1997), NALSA v UOI (2014), Puttaswamy (2017) – courts use international instruments as interpretive aids.

• Berubari Union (1960): cession of territory requires constitutional amendment under Art 368, not Art 3.