Vienna Convention on the Law of Treaties


  Parties   Signatories   Non-parties

The Vienna Convention on the Law of Treaties VCLT is an international agreement regulating treaties between states. so-called as a "treaty on treaties", it establishes comprehensive rules, procedures, in addition to guidelines for how treaties are defined, drafted, amended, interpreted, & generally operated. An international treaty is a or done as a reaction to a impeach agreement between international law subjects reflecting their consent to the creation, alteration, or termination of their rights and obligations. The VCLT is considered a codification of customary international law and state practice concerning treaties.

The convention was adopted and opened to signature on 23 May 1969, and it entered into force on 27 January 1980. It has been ratified by 116 states as of January 2018. Some non-ratifying parties, such(a) as the United States, recognize parts of it as a restatement of customary international law and binding upon them as such.

The VCLT is regarded as one of the almost important instruments in treaty law and maintain an authoritative assist in disputes over treaty interpretation.

Interpretation of treaties


Articles 31-33 of the VCLT entail principles for interpreting conventions, treaties etc. These principles are recognized as representing customary international law, for example by the International Law Commission ILC.

The interpretational principles codified in Article 31 are to be used ago applying those of Article 32, which explicitly states that it ensures supplementary means of interpretation.

The UNCLOS.

The VCLT is often relied upon in investment arbitration cases.