In international society, there are numerous declarations drafted by representatives with different legal and cultural backgrounds from all regions around the world, among which there are various milestone documents in International Law.
Vienna Convention of the Law of Treaties: Rectified in 1980, the Vienna Convention of the Law of Treaties codified the rules and norms in drafting and forming treaties between countries. Besides, it also covered regulations on negotiations, amendments, suspension, termination, as well as nullification of treaties.
Montevideo Convention on the Rights and Duties of States: As part of the international customary law, the Montevideo Convention on the Rights and Duties of State modulated the definition, rights, and duties of sovereignty states. Criteria include: Population, A defined territory, Government and Capacity to build relationships with other countries. Even though it is a treaty that was rectified by American states, it was widely regarded as the customary law concerning the formation of sovereignty states.
Charter of United Nations: Being the founding document of the United Nations, the Charter of United Nations codified major principles on international relations under the UN. Under the context of WW2, the Charter regulated that all stakeholders should tackle disputes via peaceful and goodwill measures while constituting actions to face threats from international communities.