‘Subjects of international law’ refers to the same concept as the term ‘international legal personality’. The classical distinction between subjects and objects of international law is now pretty much out of use, if not obsolete.

International legal personality means possessing rights and duties directly under international law, alongside a capacity to enforce these rights or the obligations in favour or against the person or entity. Therefore, where a treaty or custom confers enforceable rights and duties upon any entity, the latter possesses international legal personality in respect of those rights and/or duties.

Although numerous entities (ie States, individuals, international organizations, etc) may possess international legal personality, they do not all enjoy rights and duties in the same degree. For example, States can conclude treaties and use armed force to defend themselves, whereas individuals cannot. Therefore, international legal personality should be viewed from the point of view of capacity in each and every case.

The primary subjects of international law are States, because they make the law and it is they that confer rights and duties on other actors. Some degree of international legal personality is enjoyed by international organizations, individuals, non-governmental organizations such as multinational corporations, national liberation movements, and others. It all depends on the conferral of rights and duties by States in each particular case.

Recognition of States (by other States) rests on two competing theories. The first contends that recognition is irrelevant to statehood (declaratory), whereas the second argues that it is a foundational criterion of statehood (constitutive). Besides recognition of States, the recognition of governments also exists as a practice, although it is less frequent in the contemporary era.