Civil defense

Civil defense, nonmilitary measures taken to protect a nation's civilian population and its resources in case of enemy attack. Organized civil defense programs began shortly before World War II, when it was realized that powerful air forces greatly increased the wartime danger to civilians. In the United States, civil defense efforts, including warning systems, the construction and stocking of shelters, and survival planning, are directed and coordinated at the national level by the Office of Civil Defense.