In international law, a sovereign state, sovereign country, or simply state, is a nonphysical juridical entity that is represented by one centralized government that has sovereignty over a geographic area. International law defines sovereign states as having a permanent population, defined territory, one government, and the capacity to enter into relations with other sovereign states. It is also normally understood that a sovereign state is neither dependent on nor subjected to any other power or state.
Constitutionalism is a doctrine that a government's authority is determined by a body of laws or constitution. It simply means the limitation of the government, as it can only act based on the dictates of the constitution. The government must respect and obey the constitution, and avoid acting outside its authority.