This article contains a list of treaties by number of parties to the treaty. A "party" to a treaty is a state or other entity that ratifies, accedes to, approves, or succeeds to the treaty. In general, multilateral treaties are open to ratification by any state. Some treaties may also be ratified by supranational bodies, such as the European Union , and by other international organizations.
In practice, the depositary of a treaty will usually only recognise ratifications of the treaty that are performed by a state that is recognised as a state at international law. A state can be formally recognised as such by becoming a member of the United Nations; there are currently member states of the United Nations.
The only non-UN states that undoubtedly meet the standard of statehood are the Cook Islands and Niue , who have had their "full treaty-making capacity" recognised by the United Nations Secretariat. Ratifications performed by other states with more limited recognition βsuch as Abkhazia , the Republic of Artsakh Nagorno-Karabakh , the Republic of China Taiwan , Kosovo , Northern Cyprus , the Sahrawi Arab Democratic Republic Western Sahara , Somaliland , South Ossetia , and Transnistria βhave usually not been recognised by treaty depositaries as states that can ratify treaties, although there are some exceptions to this general rule.
If a state party to a treaty denounces the treaty, the state often after a certain period before the denunciation takes effect is no longer a party to the treaty, although in some cases certain parts of the treaty may continue to apply. States change over time, and often a state that ratified a treaty will cease to exist.
International law deals with this issue in two ways. First, it is possible for a state to be declared the successor state to the defunct state. In this situation, any ratifications performed by the defunct state are transferred to and attributed to the successor state.
