Key conventions & dispute settlement

The codified core of international law

The modern treaty system rests on a small set of foundational conventions whose articles you must be able to cite by number. The Vienna Convention on the Law of Treaties (VCLT), adopted 23 May 1969, in force 27 January 1980, governs how treaties are made, interpreted and terminated. Retain its load-bearing articles: Article 26 (pacta sunt servanda), Article 27 (a state may not invoke internal law to justify breach), Articles 31–33 (interpretation — ordinary meaning in context and in light of object and purpose), Article 53 (jus cogens — peremptory norms admitting no derogation), and Articles 60–62 (material breach, supervening impossibility, fundamental change of circumstances or rebus sic stantibus).

The thematic conventions

Four clusters dominate the exam. Diplomatic and consular law: the Vienna Convention on Diplomatic Relations (1961, Article 22 inviolability of mission premises, Article 29 inviolability of the diplomatic agent, Article 31 immunity from jurisdiction) and the Vienna Convention on Consular Relations (1963, Article 36 on consular access — litigated in LaGrand, Germany v. United States, ICJ 2001, and Avena, Mexico v. United States, ICJ 2004).

Law of the sea: the UN Convention on the Law of the Sea (UNCLOS, 1982, in force 1994) fixing the 12-nautical-mile territorial sea (Article 3), 24-mile contiguous zone (Article 33), 200-mile exclusive economic zone (Article 57) and continental-shelf regime (Articles 76–77).

Human rights and humanitarian law: the four Geneva Conventions of 1949 with Additional Protocols I and II (1977); the International Covenants on Civil and Political Rights and on Economic, Social and Cultural Rights (both 1966); and the Genocide Convention (1948), whose Article IX confers ICJ jurisdiction — invoked in Bosnia v. Serbia (2007) and The Gambia v. Myanmar (2019–present).

International criminal law: the Rome Statute of the International Criminal Court (adopted 17 July 1998, in force 1 July 2002), defining genocide, crimes against humanity, war crimes and — since the 2010 Kampala amendments — the crime of aggression, all governed by the principle of complementarity (Article 17).

Why memorise article numbers

Examiners test precision, not vibes. A UPSC GS-2 or FSOT answer that cites “Article 36 of the VCCR” or “Article 53 jus cogens” signals command; a vague reference to “the Vienna rules” does not. The high-yield move is to pair each convention with the dated case that operationalised it — UNCLOS with the South China Sea Arbitration (2016), the VCCR with Avena (2004), the Genocide Convention with The Gambia v. Myanmar. That pairing converts rote recall into analytical credit.

The Article 33 menu

Article 2(3) of the UN Charter obliges members to settle disputes by peaceful means; Article 33(1) enumerates the toolkit: negotiation, enquiry, mediation, conciliation, arbitration, judicial settlement, resort to regional agencies, and “other peaceful means of their own choice.” These divide into diplomatic methods (negotiation, good offices, mediation, conciliation — non-binding, party-controlled) and legal methods (arbitration and adjudication — binding third-party decision). The choice is consensual: no state may be compelled before a court without its consent.

The International Court of Justice

The ICJ, the principal judicial organ of the UN (Charter Article 92), operates under the Statute of the ICJ. Jurisdiction in contentious cases (Article 36) arises four ways: special agreement (compromis), a compromissory clause in a treaty, the optional-clause declaration under Article 36(2) accepting compulsory jurisdiction, and forum prorogatum. Only states may be parties (Article 34). Judgments are final and without appeal (Article 60) and binding only between the parties on that case (Article 59 — no formal stare decisis). The Court also renders advisory opinions (Article 65) at the request of UN organs — as in the Legality of the Threat or Use of Nuclear Weapons (1996), the Wall opinion (2004), the Chagos opinion (2019), and the climate-change opinion delivered in 2025.

Arbitration and specialised tribunals

Arbitration predates the Court: the Alabama Claims arbitration (1872) between the US and Britain is the modern template, and the Permanent Court of Arbitration (PCA), established by the 1899 Hague Convention, administers inter-state and investor-state cases, including the South China Sea Arbitration (Philippines v. China, 2016) under UNCLOS Annex VII. UNCLOS itself (Part XV, Article 287) offers a choice of forum: ITLOS (the International Tribunal for the Law of the Sea, Hamburg), the ICJ, or Annex VII/VIII arbitration. The WTO Dispute Settlement Understanding (1994) supplies a treaty-specific compulsory system through panels and the Appellate Body — the latter paralysed since December 2019 by the US blocking of member appointments.

Enforcement and its limits

Enforcement is the weak link. Under Charter Article 94(2), a party may take an unsatisfied ICJ judgment to the Security Council, which may recommend or decide measures — but the permanent-member veto can neutralise this, as Nicaragua found after winning Nicaragua v. United States (1986). This gap between adjudication and compliance is a perennial essay theme: international law is law, but its enforcement is decentralised and politically contingent.