thumb|right|275px|[[U.S. Marines and ANA soldiers on patrol during counterinsurgency operations in Marjah, Afghanistan, February 2010]]thumb|right|275px|Police question a civilian during the [[Malayan Emergency. Counterinsurgency involves action from both military and police authorities.]]

Counterinsurgency (COIN, or NATO spelling counter-insurgency) is "the totality of actions aimed at defeating irregular forces". The Oxford English Dictionary defines counterinsurgency as any "military or political action taken against the activities of guerrillas or revolutionaries" and can be considered war by a state against a non-state adversary. while modern thinking on counterinsurgency was developed during decolonization.

During insurgency and counterinsurgency, the distinction between civilians and combatants is often blurred. Counterinsurgency may involve attempting to win the hearts and minds of populations supporting the insurgency. Alternatively, it may be waged in an attempt to intimidate or eliminate civilian populations suspected of loyalty to the insurgency through indiscriminate violence.

Models

Counterinsurgency is normally conducted as a combination of conventional military operations and other means, such as demoralization in the form of propaganda, Psy-ops, and assassinations. Counter-insurgency operations include many different facets: military, paramilitary, political, economic, psychological, and civic actions taken to defeat insurgency.

To understand counterinsurgency, one must understand insurgency to comprehend the dynamics of revolutionary warfare. Counter-insurgency focuses on bridging these gaps. Insurgents take advantage of social issues known as gaps. When the gaps are wide, they create a sea of discontent, creating the environment in which the insurgent can operate.

In The Insurgent Archipelago, John Mackinlay puts forward the concept of an evolution of the insurgency from the Maoist paradigm of the golden age of insurgency to the global insurgency of the start of the 21st century. He defines this distinction as "Maoist" and "post-Maoist" insurgency.

Counterinsurgency theorists

Santa Cruz de Marcenado

The third Marques of Santa Cruz de Marcenado (1684–1732) was an early author who wrote on conventional military matters and gave suggestions on the topic of "rebellions".

Thomas-Robert Bugeaud

General Bugeaud served extensively in the French war of conquest in Algeria and was also personally present (although as a junior officer) during the Peninsular War. After he returned to France he wrote extensively about Algeria and has been cited as an early commander whose conduct contains many aspects of modern counterinsurgency doctrine, such as intelligence lead operations rather than the more "population centric" of both modern doctrines and also latter French Generals during the colonial period who developed the oil spot method.

However, once dispersed and decentralized, the irregular nature of the rebel campaigns proved a decisive counter to French superiority on the battlefield. Napoleon's army had no means of effectively combating the rebels, and in the end, their strength and morale were so sapped that when Wellington was finally able to challenge French forces in the field, the French had almost no choice but to abandon the situation.

Counterinsurgency efforts may be successful, especially when the insurgents are unpopular. The Philippine–American War, the Shining Path in Peru, and the Malayan Emergency have been the sites of failed insurgencies.

Hart also points to the experiences of T. E. Lawrence and the Arab Revolt during World War I as another example of the power of the rebel/insurgent. Though the Ottomans often had advantages in manpower of more than 100 to 1, the Arabs' ability to materialize out of the desert, strike, and disappear again often left the Turks reeling and paralyzed, creating an opportunity for regular British forces to sweep in and finish the Turkish forces off.

In both the preceding cases, the insurgents and rebel fighters were working in conjunction with or in a manner complementary to regular forces. Such was also the case with the French Resistance during World War II and the National Liberation Front during the Vietnam War. The strategy in these cases is for the irregular combatant to weaken and destabilize the enemy to such a degree that victory is easy or assured for the regular forces.

According to Liddell Hart, there are few effective counter-measures to this strategy. So long as the insurgency maintains popular support, it will retain all of its strategic advantages of mobility, invisibility, and legitimacy in its own eyes and the eyes of the people. So long as this is the situation, an insurgency essentially cannot be defeated by regular forces.

David Galula

David Galula gained his practical experience in counterinsurgency as a French Army officer in the Algerian War. His theory of counterinsurgency is not primarily military, but a combination of military, political and social actions under the strong control of a single authority.

Galula proposes four "laws" for counterinsurgency:

  1. The aim of the war is to gain the support of the population rather than control of territory.
  2. Most of the population will be neutral in the conflict; support of the masses can be obtained with the help of an active friendly minority.
  3. Support of the population may be lost. The population must be efficiently protected to allow it to cooperate without fear of retribution by the opposite party.
  4. Order enforcement should be done progressively by removing or driving away armed opponents, then gaining the support of the population, and eventually strengthening positions by building infrastructure and setting long-term relationships with the population. This must be done area by area, using a pacified territory as a basis of operation to conquer a neighboring area.

Galula contends that:

According to Galula, some of these steps can be skipped in areas that are only partially under insurgent control, and most of them are unnecessary in areas already controlled by the government.

Robert Thompson

Robert Grainger Ker Thompson wrote Defeating Communist Insurgency in 1966, wherein he argued that a successful counterinsurgency effort must be proactive in seizing the initiative from insurgents. Thompson outlines five basic principles for a successful counterinsurgency:

  1. The government must have a clear political aim: to establish and maintain a free, independent and united country that is politically and economically stable and viable;
  2. The government must function in accordance with the law;
  3. The government must have an overall plan;
  4. The government must give priority to defeating political subversion, not the guerrilla fighters;
  5. In the guerrilla phase of an insurgency, a government must secure its base areas first.

David Kilcullen

thumb|right|350px|Three Pillars of Counterinsurgency

In "The Three Pillars of Counterinsurgency", Dr. David Kilcullen, the Chief Strategist of the Office of the Coordinator for Counterterrorism of the U.S. State Department in 2006, described a framework for interagency cooperation in counterinsurgency operations. His pillars – Security, Political and Economic – support the overarching goal of Control, but are based on Information:

Kilcullen considers the three pillars to be of equal importance because