Communism
From Halopedia, the Halo wiki
Communism was a military, and cultural governing system on Earth in the 20th and 21st century, originating from Karl Marx, but was made known mostly by the Soviet Union by Vladmir Lenin and his "Bolshevik" Party. Communism was ultimately dissolved in 1992 in most nations of Earth.
The Neo-Communist hardliner, Vladimir Koslov, led a neo-communist party called the "Koslovics" which fought against the United Nations during the Interplanetary War of 2160 - 2164, and ultimately lost.