[T]he Pentagon is intensively debating an option that dates back to a still-secret strategy in the Reagan administration’s battle against the leftist guerrilla insurgency in El Salvador in the early 1980s. Then, faced with a losing war against Salvadoran rebels, the U.S. government funded or supported "nationalist" forces that allegedly included so-called death squads directed to hunt down and kill rebel leaders and sympathizers. Eventually the insurgency was quelled, and many U.S. conservatives consider the policy to have been a success—despite the deaths of innocent civilians and the subsequent Iran-Contra arms-for-hostages scandal. (Among the current administration officials who dealt with Central America back then is John Negroponte, who is today the U.S. ambassador to Iraq. Under Reagan, he was ambassador to Honduras.) ***Death squads.
[O]ne Pentagon proposal would send Special Forces teams to advise, support and possibly train Iraqi squads, most likely hand-picked Kurdish Peshmerga fighters and Shiite militiamen, to target Sunni insurgents and their sympathizers, even across the border into Syria, according to military insiders familiar with the discussions. It remains unclear, however, whether this would be a policy of assassination or so-called "snatch" operations, in which the targets are sent to secret facilities for interrogation. ***
[W]ith the U.S. Army strained to the breaking point, military strategists note that a dramatic new approach might be needed—perhaps one as potentially explosive as the Salvador option.
Yes, I am sure that is the piece that was missing from the Iraqi democratization puzzle -- death squads.