Low-intensity warfare

A low-intensity conflict (LIC) is a military conflict, usually localised, between two or more state or non-state groups which is below the intensity of conventional war. It involves the state's use of military forces applied selectively and with restraint to enforce compliance with its policies or objectives. The term can be used to describe conflicts where at least one or both of the opposing parties operate along such lines.

Low-intensity operations consist of the deployment and use of soldiers in situations other than war. For states, these operations are usually conducted against non-state actors and are given terms like counter-insurgency, anti-subversion, and peacekeeping.Violent non-state actors often conduct low-intensity operations against states, often in insurgencies.

Low-intensity conflict is defined by the US Army as:

... a political-military confrontation between contending states or groups below conventional war and above the routine, peaceful competition among states. It frequently involves protracted struggles of competing principles and ideologies. Low-intensity conflict ranges from subversion to the use of the armed forces. It is waged by a combination of means, employing political, economic, informational, and military instruments. Low-intensity conflicts are often localized, generally in the Third World, but contain regional and global security implications.

The manual also says:

... successful LIC operations, consistent with US interests and laws, can advance US international goals such as the growth of freedom, democratic institutions, and free market economies. ... US policy recognizes that indirect, rather than direct, applications of US military power are the most appropriate and cost-effective ways to achieve national goals in a LIC environment. The principal US military instrument in LIC is security assistance in the form of training, equipment, services and combat support. When LIC threatens friends and allies, the aim of security assistance is to ensure that their military institutions can provide security for their citizens and government. ... The United States will also employ combat operations in exceptional circumstances when it cannot protect its national interests by other means. When a US response is called for, it must be in accordance with the principles of international and domestic law. These principles affirm the inherent right of states to use force in individual or collective self-defense against armed attack.

...
Wikipedia