The Vienna Convention on the Law of Treaties is a multilateral treaty that codifies existing customary international law governing the formation, interpretation, application, amendment, and termination of treaties between states. It was drafted by the International Law Commission of the United Nations, adopted on May 22, 1969, opened for signature the following day, and entered into force on January 27, 1980. The convention introduced the concept of jus cogens, peremptory norms of international law from which no derogation is permitted, into positive international law, and applies only to written treaties concluded between states, with a related 1986 convention extending comparable rules to treaties involving international organizations. The International Court of Justice has repeatedly cited the convention as reflecting customary international law even in disputes involving states that are not parties to it, though which of its provisions bind non-parties as customary law versus specific treaty obligations remains a subject of periodic legal debate.
Facts
Key ProvisionAdopted on 23 May 1969 and in force from 1980, it codifies the customary international law governing how treaties between states are made, interpreted, amended and terminated. Article 26 states the principle of pacta sunt servanda, that every treaty in force binds the parties and must be performed by them in good faith; Article 31 sets out the general rule of interpretation, that a treaty is to be interpreted in good faith according to the ordinary meaning of its terms in their context and in light of its object and purpose; Article 60 governs termination or suspension for material breach; and Article 53 recognizes jus cogens, peremptory norms of general international law from which no derogation is permitted and against which a conflicting treaty is void. 1 Classification
Document Type Original Language Connections
Associated With
The Law of Treaties convention codifies the general rules of treaty-making and interpretation that govern the Diplomatic Relations convention as a treaty in its own right.
Source Vienna Convention on the Law of Treaties (UN Office of Legal Affairs)
Influenced
Its foundation in state consent, no state is bound without agreeing to be, treats treaty-making itself as an exercise of sovereignty.
Source Vienna Convention on the Law of Treaties (UN Office of Legal Affairs)
Influenced By
The United Nations International Law Commission drafted the Vienna Convention on the Law of Treaties.
Sources
1. Vienna Convention on the Law of Treaties (UN Office of Legal Affairs)
United Nations Office of Legal AffairsDocument type, description
The Vienna Convention on the Law of Treaties is a multilateral treaty that codifies existing customary international law governing the formation, interpretation, application, amendment, and termination of treaties between states.
- Associated With: Vienna Convention on Diplomatic Relations
- Influenced: Sovereignty
View the Source 2. Wikidata: Vienna Convention on the Law of Treaties
- Wikidata Q239768, class allow-list match, case-insensitive label variant (w-bbfill-smallsix2-0926/resolve_ci.ps1)
- Wikidata Q239768 via P407 (w-bbfill-smallsix2-0926/propfill_varchar.ps1)
View the SourceVienna Convention on the Law of Treaties (Wikipedia)
In Group: Treaties and Agreements of 1946 to 1989, Lead paragraphQuote, In Group: Treaties and Agreements of 1946 to 1989, Lead paragraph
The Vienna Convention on the Law of Treaties was adopted and opened to signature on 23 May 1969, became effective on 27 January 1980, and has been ratified by 119 sovereign states as of May 2026.
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