Centralism

Unitarianism is a non-quadrant ideology that advocates for a Unitary State. A unitary state is a state in which political power is held by a single central government, instead of it being spread amongst states, provinces, federations or the like. Despite wanting centralized power, it is not inherently authoritarian, as one can argue a libertarian central government, or even an authoritarian decentral government. It can be seen as the opposite of  Confederalism.

Further Information
Wikipedia

https://en.wikipedia.org/wiki/Unitary_state