and local personnel, has three general components, although they may not all be part of a specific mission: guerrilla force that engages in direct combat with enemy forces. Depending on the situation, this force may be full-time or part-time, and often stays hidden when not in combat. underground, a mixture of covert and clandestine functions. Covert functions include sabotage and psychological warfare. Clandestine missions include intelligence gathering and helping key personnel escape from the area of operation. auxiliary, whose activities should remain clandestine. Its functions include supply, transportation, acquisition or manufacture of weapons, recruiting, counter-intelligence, reception of personnel and equipment arriving clandestinely, medical services, finance, etc. This support organization can be urban or rural. Especially in urban warfare, the guerrilla force and underground may be integrated. Targeting Detailed targeting may be conducted by separate special reconnaissance or other special operations intelligence resources. The UW unit, however, will almost certainly identify and prioritize targets on its own. One relevant U.S. doctrine is identified by the CARVER mnemonic, although CARVER tends to emphasize air, artillery, direct action raids rather than UW: Criticality: How important, in a strategic context, is the target? What effect will its destruction have on other elements of the target system? Is it more important to have real-time surveillance of the target (e.g., a road junction) than its physical destruction? Accessibility: Can an SR team reach or sense the target, keep it under surveillance for the appropriate time, and then exfiltrate after the target is struck? Recuperability: When the target is destroyed by fire support or direct action, in the case of DA missions, can the enemy repair, replace, or bypass it quickly, minimum resources? If so, it may not be a viable target. Vulnerability: do SR (including DA) and supporting units have the capability to destroy the target? Effect: Beyond pure military effect, what are the political, economic, legal, and psychological effects of destroying the target? How would the attack affect local civilians? Recognizability: Can the target be recognized clearly, by SR and attack forces, under the prevailing weather, light, and in its terrain? If there are critical points within the target, they also must be recognizable by the means of destruction used. Major target systems vulnerable to UW interdiction operations include railway, highway, waterway, airway, communication, power, water supply, fuel supply, and air defense systems. Means of interdiction To interdict enemy operations, the resistance can use direct