Low-intensity conflict
A primary consideration is to avoid depending on fixed bases and depots, which are comparatively easy for conventional units to locate and destroy. Mobility and speed are the keys; wherever possible, the guerrilla must live off the land or draw support from the civil population in which it is embedded. In that sense, "the people" become the guerrilla's supply base. The financing of terrorist or guerrilla activities ranges from direct individual contributions (voluntary or non-voluntary) to the actual operation of business enterprises by insurgent operatives to bank robberies and kidnappings to the complex financial networks that are based on kin, ethnic and religious affiliation used by modern jihadist/jihad organizations.
Permanent and semi-permanent bases form part of the guerrilla logistical structure, which are usually located in remote areas or in cross-border sanctuaries that are sheltered by friendly regimes. They can be quite elaborate, such as in the tough VC/NVA fortified base camps and tunnel complexes encountered by US forces during the Vietnam War. Their importance can be seen by the hard fighting sometimes engaged in by communist forces to protect those sites. However, when it became clear that defense was untenable, communist units typically withdrew without sentiment.

Terrain: Guerrilla warfare is often associated with a rural setting, which was indeed the case with the definitive operations of Mao and Giap, and the mujahadeen of Afghanistan. Guerrillas, however, have successfully operated in urban settings, such as in Argentina and Cyprus. In both cases, guerrillas rely on a friendly population to provide supplies and intelligence. Rural guerrillas prefer to operate in regions providing plenty of cover and concealment, especially heavily forested and mountainous areas. Urban guerrillas, rather than melting into the mountains and jungles, blend into the population and also depend on a support base among the people. Rooting guerrillas out of both types of areas can be difficult.

Foreign support and sanctuaries: Foreign support in the form of soldiers, weapons, sanctuary, or statements of sympathy for guerrillas is not strictly necessary, but it can greatly increase the chances of an insurgent victory. Foreign diplomatic support may bring the guerrilla cause to international attention, putting pressure on local opponents to make concessions or garnering sympathetic support and material assistance. Foreign sanctuaries can add heavily to guerrilla chances, furnishing weapons, supplies, materials, and training bases. Such shelter can benefit from international law, particularly if the sponsoring regime is successful in concealing its support and in claiming plausible deniability for attacks that are by operatives based in its territory.
The VC and NVA made extensive use of such international sanctuaries during their conflict, and the complex of trails, way-stations and bases snaking through Laos and Cambodia (the famous Ho Chi Minh Trail) was the logistical lifeline that sustained their forces in South Vietnam. Another case in point is the Mukti Bahini guerrillas, who fought alongside the Indian Army in the 14-day Bangladesh Liberation War in 1971 against Pakistan, which led to the independence of Bangladesh. In the post-Vietnam era, al-Qaeda also made effective use of remote territories, such as Afghanistan under the Taliban regime, to plan and execute its operations. That foreign sanctuary eventually broke down with American attacks against the Taliban and al-Qaeda after the September 11 attacks.

Guerrilla initiative and combat intensity: Since they can choose when and where to strike, guerrillas usually have the tactical initiative and the element of surprise. The planning for an operation may take weeks, months, or even years with a constant series of cancelations and restarts, as the situation changes. Careful rehearsals and "dry runs" are usually conducted to work out problems and details. Many guerrilla strikes are not undertaken unless clear numerical superiority can be achieved in the target area, a pattern typical of VC/NVA and other "people's war" operations. Individual suicide bomb attacks offer another pattern, typically involving only the individual bomber and his support team, but they too are spread or metered out based on prevailing capabilities and political winds.
Whatever approach is used, the guerrilla holds the initiative and can prolong his survival by varying the intensity of combat. Attacks are spread out over quite a range of time, from weeks to years. During the interim periods, the guerrilla can rebuild, resupply, and plan. During the Vietnam War, most communist units, including mobile NVA regulars using guerrilla tactics, spent only a few days per month fighting. While they might be forced into an unwanted battle by an enemy sweep, most of the time was spent in training, intelligence gathering, political and civic infiltration, propaganda indoctrination, construction of fortifications, or foraging for supplies and food. The large numbers of such groups striking at different times, however, gave the war its "around-the-clock" quality.

Low-intensity counter operations or counter-guerrilla warfare: 

Principles: The low-intensity fighter or guerrilla can be difficult to beat, but certain principles of counter-insurgency warfare are well known since the 1950s and 1960s and have been successfully applied.

Classic guidelines: The widely distributed and influential work of Sir Robert Thompson, counter-insurgency expert in Malaysia, offers several such guidelines. Thompson's underlying assumption is that of a country minimally committed to the rule of law and better governance. Numerous other regimes, however, give such considerations short shrift, and their counterguerrilla operations have involved mass murder, genocide, starvation as well as the massive spread of terror, torture and execution. The totalitarian regimes of Stalin and Hitler are classic examples, as are the lesser but comparable measures of dictatorships fighting "dirty wars" in South America. Elements of Thompson's moderate approach are adapted here:

A viable competing vision that comprehensively mobilizes popular support. There must be a clear political counter-vision, which can overshadow, match, or neutralize the guerrilla vision. That can range from granting political autonomy to economic development measures in the affected region. The vision must be integrated approach, involving political, social, and economic and media influence measures.
Reasonable concessions where necessary. Action also must be taken at a lower level to resolve legitimate grievances. It may be tempting for the counter-insurgent side simply to declare guerrillas "terrorists" and to pursue a harsh liquidation strategy. Brute force, however, may not be successful in the long run. Action does not mean capitulation, but sincere steps, such as removing corrupt or arbitrary officials, cleaning up fraud, or collecting taxes honestly can do much to undermine the guerrillas' appeal.
Economy of force. The counter-insurgent regime must not overreact to guerrilla provocations, which may indeed be what the guerrilla seeks to create a crisis in the civilian morale. Police level actions should guide the effort and take place in a clear framework of legality, even if under a state of emergency. Civil liberties and other customs of peacetime may have to be suspended, but again, the counter-insurgent regime must exercise restraint and cleave to orderly procedures. Clear steps must be taken to curb brutality and retaliation by the security or "freelance" forces.
Big unit action may sometimes be necessary. If police action is not sufficient to stop insurgents, military sweeps may be necessary. Such "big battalion" operations may be needed to break up significant guerrilla concentrations and split them into small groups that can be controlled by combined civic-military action.
Mobility. Mobility and aggressive small unit action is extremely important for the counter-insurgent regime. Heavy formations must be lightened to aggressively locate, pursue, and fix insurgent units. Huddling in static strongpoints simply concedes the field to the insurgents, who must be kept on the run constantly by aggressive patrols, raids, ambushes, sweeps, cordons, etc.
Systematic intelligence effort. Every effort must be made to gather and organize useful intelligence. A systematic process must be set up to do so, ranging from casual questioning of civilians to structured interrogations of prisoners. Creative measures must also be used, including the use of double agents or even bogus "liberation" or sympathizer groups to help reveal insurgent personnel or operations.
Methodical clear and hold. An "ink spot" clear and hold strategy must be used by the counter-insurgent regime, which divides the conflict area into sectors and assigns priorities between them. Control must expand outward like an ink spot on paper, systematically neutralizing and eliminating the insurgents in one sector of the grid, before proceeding to the next. It may be necessary to pursue holding or defensive actions elsewhere while priority areas are cleared and held.
Careful deployment of mass popular forces and special units. Specialist units can be used profitably, including commando squads, long range reconnaissance, "hunter-killer" patrols, defectors who can track or persuade their former colleagues like the Kit Carson units in Vietnam, and paramilitary style groups. Strict control must be kept over specialist units to prevent the emergence of violent vigilante-style reprisal squads that undermine the government's program. Mass forces include village self-defence groups and citizen militias organized for local defence and security.
Foreign assistance must be limited and carefully used. Such aid should be limited to material and technical support and small cadres of specialists. Unless that is done, the foreign helper may find itself "taking over" the local war and being sucked into a lengthy commitment, thus providing the guerrillas with valuable propaganda opportunities. Such a scenario occurred with the United States in Vietnam.

Low-intensity operations: Low-intensity operations consist of the deployment and use of soldiers in situations other than war.