REUTERS/Stringer
An insurgency is the manifestation of popular will, not exclusively guerrilla and terrorist actions. There can be numerous reasons why and how an insurgency begins, but once it has endured over a period of time the popular "cause" becomes irrelevant. Eventually a fence-sitting population will side with the projected winner of the conflict as backing a losing side is a potential death sentence. Survival is the most basic instinct and most important factor during an insurrection.
The political nature of an insurgency is tragically often overlooked. Western militaries go to great lengths to separate politics from military action but this is a doctrine for failure. War is an extension of politics and insurgency is a form of armed politics. While the Defense Department excludes itself from politics, U.S. diplomats in Kabul and Baghdad interact with host nation government officials as if they are representatives from a well-established European nation, not opportunistic collaborators. Failure to respond to the political nature of an insurgency is a "whole of government" U.S. failure.
Strategies for disrupting insurgent violence:
Hammer and Anvil:
Kill / Capture missions carried out within a controlled environment. Conventional troops will secure the population while other units conduct raiding operations to dismantle the known insurgent network. Kill / Capture missions alone may remove known members but ultimately prove futile if insurgents can still recruit.
Amnesty:
There have been few successful counterinsurgency campaigns absent an amnesty program. Without a means to surrender, host nation governments force insurgents to fight to the death. Insurgencies can be marginalized and isolated from the population, but absolute destruction is only possible in a dictatorial police state. Former insurgents entering into a "witness protection" styled program can be used in propaganda to crush the morale of active insurgents while providing critical information on insurgents at large.
Network Corruption:
Insurgent groups are structured dynamic social networks of cells based upon previous or recent trusted relationships. When the trust of a cell erodes, the network begins to collapse. Arrest five insurgents, ask four to spy on the insurgency, and release all of them. The four solicited insurgents will suspect the fifth one is a traitor and possibly have him killed. Paranoia will grow if this process is repeated continuously.
These efforts conducted simultaneously will maximize chances for success in mitigating violence, but will only provide a window of opportunity for the host nation government to settle legitimate political grievances that spawned the insurgency. Removing the "cause" from the insurgency is required to isolate and marginalize the remaining insurgents from the population in order to achieve a true victory.