The Law Governing Treaty Relations between Parties to the Vienna Convention on the Law of Treaties and States Not Party to the Convention

The Vienna Convention on the Law of Treaties (the Convention), concluded on May 23, 1969, entered into force on January 27, 1980. It thus took more than 10 years for 35 states to ratify the instrument or to accede to it. Although its entry into force may hasten ratification and accession somewhat in other states, it will probably be a very long time before a large majority of states are parties to the Convention. Therefore, international treaty practice will long be faced with the conclusion of treaties between or among states that are parties to the Convention and other states.