What is the importance of the CIA in the nonfiction book, Thirteen Days; a Memoir of the Cuban Missile Crisis?

Created along with the National Security Council by the National Security Act of 1947, the CIA charged with gathering and analyzing information overseas for use by policymakers. As part of this mission it flies U-2 spy planes over Communist territories, taking high-altitude surveillance pictures. When it finds proof of Soviet missiles and nuclear weapons in Cuba, the CIA briefs high officials using charts and photographs that are nearly unintelligible to laymen, but stunning and surprising. Thereafter, John McCone, Director of the CIA, is primarily responsible for keeping Ex Comm abreast of breaking news, although Defense Secretary Robert McNamara clearly has his own independent channels.