All nonmilitary actions taken to reduce loss of life and property resulting from enemy action.
The threat of aerial attack on cities led to organized civil-defense planning in World War II. The British government provided its people with gas masks, and nearly all countries trained citizens in fire fighting, rescue, and first aid. Blackouts reduced the glow from city lights that could guide enemy pilots; sirens warned of bombing attacks, and citizens took cover in air-raid shelters, basements, and subways. The postwar threat of nuclear attack prompted civil authorities to mark buildings that offered the best shelter from fallout . By the 1970s the West had largely abandoned civil-defense preparations as it became clear that surviving a direct nuclear attack was unlikely.