From the Washington Post by Greg Bruno The Role of the 'Sons of Iraq' in Improving Security

The decision to cut ties with AQI was dubbed the "Anbar Awakening" by Iraqi organizers, and has been hailed as a turning point in the U.S.-led war effort. Gen. David H. Petraeus, the top U.S. commander in Iraq, told lawmakers in Washington the uprising has reduced U.S. casualties, increased security, and even saved U.S. taxpayers money. "The savings and vehicles not lost because of reduced violence," the general said in April 2008, "far outweighed the costs of their monthly contracts." Yet the future of the Awakening -- Sahwa in Arabic -- is a matter of increasing debate in foreign policy circles. Internal disputes within the predominantly Sunni groups have threatened the stability of the revolt, some experts say. Sunni groups have also complained about low pay and a lack of opportunities for employment within Iraq's army and police forces. CFR Senior Fellow Steven Simon writes in Foreign Affairs that while the Sahwa strategy may bring short-term stability to Iraq, the long-term effect could be runaway "tribalism, warlordism, and sectarianism."
Wikipedia's entry on Paramilitaries in Colombia

Paramilitary groups, whether of private or public origin, having legal or illegal support, were originally organized during the Cold War proxy wars as small groups, being created as either a preemptive or reactive consequence to the real or perceived growing threat represented by the actions of guerrillas and militant political activists of Marxist-Leninist ideology.