"This following commentary is an exploration of the overwhelming need to maintain a strategic perspective in fighting an insurgency, illustrated by close examination of the continuing insurgency in El Salvador. We believe that in El Salvador, as in all other insurgencies of this sort, three strategic considerations must be kept in mind: The insurgent is dedicated to total victory and all his actions must be judged accordingly; the fundamental goal of the insurgent is not military, but political, namely to undermine the legitimacy of the government; and finally, conducting a counterinsurgency strategy cannot be done in a business-as-usual manner--a special organization and tactics are necessary."
McNair Paper No. 8
National Defense University, Institute for National Strategic Studies: http://www.ndu.edu/inss