Answer:
Historians believe that the FCDA used civil defense measures as a psychological tool to convince civilians that preventive measures could be taken.
Step-by-step explanation:
At that time , the FCDA told the people that they can detect nuclear attack from far away and will have enough time to inform the citizens and help them evacuate before nuclear attack hits.
This can be seen as a propaganda to reduce public's concern for nuclear warfare because escaping missile attacks are almost impossible due to the speed and the magnitude of the damage. Historians believe that FCDA only saying it to prevent chaos,