The Encyclopedia is a project of the Geneva Academy of International Humanitarian Law and Human Rights launched on 2 December 2013. The Enyclopedia aims to provide accurate, up-to-date information on weapons, the effects of their use, and their regulation under public international law, in a format that is accessible to non-specialists.+ Find out more
In most cases, signing an international treaty does not make the signatory a state party, thereby requiring it to implement the treaty’s provisions (this requires the further act of ratification).
A signatory state must not, though, undertake any action that would ‘defeat’ (i.e. frustrate or undermine) the object and purpose of the treaty. This obligation is set out in Article 18 of the 1969 Vienna Convention on the Law of Treaties, a provision that has attained the status of customary international law applicable to all states.
Last updated on: 08 August 2017