In which system does sovereignty reside solely with the national government?

In a unitary system, sovereignty is held entirely by the national government, meaning that the central authority maintains ultimate power over all subnational entities. This centralization enables the national government to create laws, regulate, and govern without the necessity for consent from local or regional governments. Local entities may have administrative powers, but these are granted by the central government, which can also revoke them.

This system contrasts sharply with a federal system, where power is shared between the national and state governments, allowing for governance at multiple levels, and a confederate system, where states hold most of the power and the national government has very limited authority. A republican system refers more to a representative form of government rather than the distribution of sovereignty. The unitary system's concentration of power allows for streamlined decision-making and uniform policy implementation across the entire nation.