Independent voices from the TWT Communities

At hand is one of the more important books ever published about the CIA - a working insider's account of the aerial reconnaissance program that was, in many opinions, the cardinal Cold War achievement of America's intelligence community.
Mr. Brugioni notes that Eisenhower approved the U-2 flights only after the Soviets curtly rejected his offer of an "open skies" policy that would permit mutual overflights that would prevent either side from launching a surprise attack a la Pearl Harbor.
As Mr. Brugioni correctly notes, "The USSR's size, internal security measures, and close monitoring of embassy personnel and visitors were not conducive to old-fashioned collection methods" - i.e., spying.