What is it called when socialism is taken to the extreme

Authoritarian socialism, or socialism from above,[1] is an economic and political system supporting some form of socialist economics while rejecting political liberalism. As a term, it represents a set of economic-political systems describing themselves as socialist and rejecting the liberal-democratic concepts of multi-party politics, freedom of assembly, habeas corpus and freedom of expression, whether due to fear of the counter-revolution or as a means to socialist ends. Several countries, most notably the Soviet Union, China and their allies, have been described by journalists and scholars as authoritarian socialist states.