The power of a nation state to determine its own government is called: SOVEREIGNITY.
The word "Sovereignity" arises from the Latin superanus, meaning "chief" and the Latin regnum, meaning "kingship". It is the full right and power that a country has to govern itself or another country or state, without any interference from outside sources or bodies. In political theory, sovereignty is a substantive term designating supreme authority over some polity.
