Right-wing paramilitary groups in Colombia are paramilitary groups acting in opposition to revolutionary Marxist–Leninist guerrilla forces and their allies among the civilian population. These right-wing paramilitary groups control a large majority of the illegal drug trade in Colombia of cocaine and other substances. The Colombian National Centre for Historical Memory has estimated that between 1981 and 2012 paramilitary groups have caused 38.4% of the civilian deaths, while the Guerillas are responsible for 16.8%, 10.1% by the Colombian Security Forces and 27.7% by non-identified armed groups.