The Revolutionary Armed Forces of Colombia are the largest guerilla group in the country. The leftist FARC were formed in 1962 as the military faction of the Communist Party. Despite its claim of being the "People Army," the FARC routinely terrorize and brutalize the Colombian populace. The vast majority of the groups funding comes from its drug trafficking and kidnapping activities.

President Alvaro Uribe's administration has taken a hard line stance against the FARC and has managed to curtail it's activities a bit. But under the ruthless command of Manuel Marulanda Velez ("Tirofijo" - "Sureshot") and Jorge Briceno (Mono Jojoy), the FARC remains 10,000 to 15,000 strong, intent on waging guerrilla warfare on Colombia and seeking to exert political influence through the use of human pawns. The BBC reported in 2000 that the FARC is increasingly targeting children for recruitment. According to H. Paz, a former member of the Colombian military, many of them join in the hopes of bettering their families' lives and they follow orders, including guarding the FARC's kidnapping victims, without understanding what they are doing or what the FARC's aims and tactics are. "Some of these kids are so young, Paz says, "the rifles they carry are bigger than they are."

The National Liberation Army of Colombia is a much smaller leftist guerrilla group than the FARC, with perhaps half to one third of the forces as the FARC. Despite their smaller numbers, they have also succeeded in financing their organization through drug trafficking, kidnapping and extortion.

The United Self-Defense Forces of Colombia is an association of right wing paramilitary groups that, like their Marxist adversaries, have found extortion and kidnapping a lucrative business. They have killed civilian, most of them peasent farmers, and have been accused by Amnesty International of violating human rights on a broad scale.