Duck and Cover

Civil defense or civil protection is an effort to protect the citizens of a state from military attack. It uses the principles of emergency operations: prevention, mitigation, preparation, response, or emergency evacuation, and recovery. Programmes of this sort were initially discussed at least as early as the 1920s and were implemented in many countries, but only became widespread in the USA after the threat of nuclear weapons was realized.
Since the end of the Cold War, the focus of civil defense has largely shifted from military attack to emergencies and disasters in general. The new concept is described by a number of terms, each of which has its own specific shade of meaning, such as crisis management, emergency management, emergency preparedness, contingency planning, emergency services, and civil protection. In some countries, civil defence is seen as a key part of "total defense". For example in Sweden, the Swedish word totalförsvar refers to the commitment of a wide range of resources of the nation to its defence - including to civil protection.