Legislation is an international instrument that sets new standards of common law for a large number of states. Compliance with a treaty can become an issue in two particular circumstances. A contract may be terminated or affected by other means when a state is replaced, in whole or in part, by another state or a new state. This was, for example, a critical issue for some African states after gaining independence. Armed conflicts may also end or suspend a treaty while hostilities continue. Article 60 of the Vienna Convention also provides for the situation that arises when a contracting party constitutes a substantial violation of its provisions. Such an offence can be considered the reason for the termination of the treaty by other states. Similarly, a fundamental change from the original circumstances of the contract can be invoked as a reason for termination. There are different types of agreements, such as bilateral agreements between two states or agreements that are multilateral between several states. A bilateral treaty is an agreement between two states that establishes reciprocal rights and obligations between them. Unless expressly stated by both parties, bilateral agreements do not confer rights or obligations on another state. A multilateral treaty is an agreement between three or more states.
Treaties are also known by several alternative names, including conventions, agreements, pacts and alliances. Whatever its name, a contract is a contractual form of the agreement between its parties that are bound according to the terms of their agreement. This raises the question of how a contract can be a source of law that exceeds the treaty obligations. The answer is that some contracts have a general legal status and have an effect, unlike more specific contractual agreements, such as . B between two or a small number of states. The former are considered contracts of law. In practice, the custodian of a treaty generally recognizes only ratifications of the treaty by a state recognized as a state by international law. A state can be formally recognized as such by becoming a member of the United Nations; Currently, 193 UN member states.
The only non-UN countries that undoubtedly meet state standards are the Cook and Niue Islands, whose “total contractual capacity” has been recognized by the UN secretariat.  Vatican City is also widely recognized as being able to legally ratify treaties and has been recognized by the UN General Assembly as an observer state without a member state.  [b] After the adoption by the United Nations General Assembly of a resolution granting the State of Palestine observer status, UNG began to recognize its right to ratification of the treaties. ratifications by other limited recognition states – such as the Republic of China (Taiwan); Le Kosovo; northern Cyprus; Somaliland; Sahrawi Arab Democratic Republic (Western Sahara); South Ossetia; Abkhazia; transnistria; and Nagorno-Karabakh – have generally not been recognized by treaty custodians as states that can ratify treaties, although there are some exceptions to this general rule. The IHR (2005) is an international agreement between 194 States Parties and the World Health Organization on surveillance, sunshine and response to all events that could pose a threat to international public health. The objective of the IHR (2005) is to prevent, protect, control and respond to a public health response to the spread of diseases internationally, in a manner adapted to public health risks, limited to them, avoiding unnecessary intervention in international transport and trade.