police state

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A state in which the government exercises rigid and repressive controls over the social, economic, and political life of the people, especially by means of a secret police force.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A nation or state whose government exercises strict and repressive control of the people, by means of police.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a country that maintains repressive control over the people by means of police (especially secret police)