Communism
From Halopedia, the Halo wiki
Communism was a military, and cultural governing system on Earth in the 20th century, originating from Karl Marx, but which was made known mostly by the Soviet Union. Communism was ultimately dissolved during the 1990's in some nations of Earth.
The Neo-Communist hardliner, Vladimir Koslov, led a communist belief system called the Koslovics which fought against the UN during the Interplanetary War of 2160 - 2164.