Civil defense is an effort to defend civilian society from military attack. Like emergency operation, it has four basic tasks: mitigation, preparation, response, and recovery. In a civil defense context, these usually have different tasks.
Mitigation is the process of actively preventing the war or the release of nuclear weapons. It includes policy analysis, diplomacy, political measures, and more military responses such as a National Missile Defense and Air defense.
Preparation consists of building shelters, and prepositioning information, supplies and emergency infrastructure. For example, most larger cities in the U.S. now have emergency operations centers that can perform civil defense coordination. Other measures would include continuous government inventories of grain silos and fuel storage systems, and the dispersal of truck-transportable bridges, water purification, mobile refineries and other aids to speed civil recovery.
Response consists first of warning civilians so they can enter shelters and protect assets. Afterwards, trained civilians can perform up to 95% of rescues from damaged structures, when organized in community emergency response teams.
Recovery consists of rebuilding damaged infrastructure, buildings and production.
Preparation for recovery can be very helpful. If mitigating resources are dispersed before the attack, cascades of social failures can be prevented. For example, a crucial need after a general nuclear attack would be diesel fuel to transport every other item for recovery. However, oil refineries are large, immobile, and probably at risk as targets. The solution would be to preposition small, dispersed truck-mounted diesel refineries near oil fields and storage depots. There are similar needs for bridges, communication, electric power, steel, concrete, food and potable water.
Relatively small investments in recovery aids can speed up recovery by months or years, and thereby prevent millions of deaths by hunger, cold and disease.