What Makes a State, and How Borders Form

International law offers no single, universally binding definition of a state, but the most widely cited starting point is the Montevideo Convention on the Rights and Duties of States, signed in 1933. It lists four qualifications: a permanent population, a defined territory, a government, and the capacity to enter into relations with other states. These criteria are useful as a checklist, yet they leave open the separate and often more consequential question of recognition — whether other states choose to treat an entity as a fellow sovereign. The "declaratory" theory holds that statehood exists independently of recognition, which merely acknowledges a fact; the "constitutive" theory holds that recognition by other states is what brings a state into legal existence in practice. This unresolved tension explains why entities such as Kosovo, Taiwan, and Palestine are treated as states by some governments and international organizations and not by others, despite each meeting most or all of the Montevideo criteria on the ground.