From the book:One of the first tasks assigned to me by the President, after I assumed responsibility for the Federal Civil Defense Program last August, was to give the American people the facts they need to know about the dangers of a thermonuclear attack and what they can do to protect themselves. This booklet attempts to provide the facts. The factual information in this booklet has been verified by independent scientific authority, and represents the best consensus of the scientific community that we can establish. The booklet also describes the national civil defense program. This program necessarily rests on judgments about what are prudent precautions in the light of our knowledge of what might happen and our evaluation of scientific facts. Judgments may differ. It is my considered judgment that this is a reasonable and prudent program—and that it is the best program we can have, measured against the other priorities of our national life.Secretary of Defense