The 1986 accident at Chernobyl provided a major impetus for broadening the geographical scope of application of the international nuclear liability regime. The Paris Convention is primarily adhered to by Western European countries while the Vienna Convention is primarily adhered to by Eastern European countries. In spite of the similarity between the Paris and Vienna Conventions, their existence does not provide a single uniform third party liability regime for all countries which are parties to either convention. The two conventions operated in isolation from each other, so that each convention benefited only victims within the territory of its own contracting parties.
In 1988, the adoption of the Joint Protocol relating to the Application of the Vienna Convention and Paris Convention created a "bridge" between the two conventions. Since its entry into force on 27 April 1992, states party to either the Paris Convention or the Vienna Convention as well as to the Joint Protocol receive the benefits of both conventions. Thus, where a nuclear incident occurs for which an operator in a Paris Convention/Joint Protocol state is liable and damage is suffered by victims in a Vienna Convention/Joint Protocol state, those victims will be able to claim compensation for their damage against the liable operator in essentially the same manner and to the same extent as if they were victims in a Paris Convention State; the reverse is equally true.
The Joint Protocol ensures that only one of the two conventions will apply to any particular nuclear incident and both the liable operator and the amount of its liability are determined by the convention to which the state, in whose territory the liable operator's installation is situated is a party. The Joint Protocol applies not only to the original Paris and Vienna conventions but also to any amendments to either convention which are in force for a contracting party to the Joint Protocol.
The Director-General of the International Atomic Energy Agency is depositary for the Joint Protocol.