Twenty years later, it is not enough to simply explain how the NSA is organized or the history of its creation. For "Body of Secrets," Bamford issued dozens of FOIA requests and would badger the NSA every few days about them. He waded through the papers at the National Archives, the Naval War College, the National Defense University -- even at the NSA's own museum. And with the Cold War over, he found that many of the actual intercept operators -- the people staffing the eavesdropping stations on ships, planes and remote corners of the planet -- were willing to talk.

Among the more shocking things Bamford learned is that in 1962, the U.S. Joint Chiefs of Staff approved something called Operation Northwoods. Fortunately never implemented, it involved committing random acts of terror on Americans in the United States and then blaming them on Cuba. Most of the documents detailing this Bamford found in the National Archives, among the thousands of papers the Joint Chiefs of Staff released about the Cuban missile crisis.

In 1967, the Israeli military attacked and destroyed the USS Liberty, a spy ship that had eavesdropped on an Israeli massacre of surrendered Egyptian soldiers in the Sinai. The ship's intercepts were destroyed, but the NSA also had spy planes eavesdropping. The details, including President Johnson's coverup to save the Jewish vote in the next election, were in a box in the back of the NSA Museum. They were in a public place, but no one had bothered to look at them before.

In 1975, the NSA tapped the undersea cable connecting Russia's Kamchatka Peninsula with the headquarters of the Soviet Pacific fleet. Operation Ivy Bells was the agency's most secret operation at the time, but Bamford found the man in charge of it to be very open and cooperative.

Even the NSA was more forthcoming this time around. Bamford started asking for interviews in 1998. First it performed its usual stonewalling routine, but gradually it relented. Bamford believes that the NSA finally got the message that the book was going to be written and that it would be better off telling its side of the story. Bamford started receiving documents, getting interviews, being taken on tours. He also credits the movie "Enemy of the State" with helping to turn things around. The movie depicts employees of the NSA as black-wearing, assassinating, privacy-violating villains. Air Force Lt. Gen. Michael Hayden, the current NSA director, believes that if agency officials don't come out and say what the agency is and what it does, then Hollywood will do it for them. Given that choice, Bamford is clearly the lesser of two evils.

The result is a book that casts the NSA in a pretty good light. It's good at collecting intelligence, but is regularly thwarted by a government with bad intentions. In 1964, the USS Maddox was spying in the Gulf of Tonkin, off the coast of Vietnam. Believing the ship to be directing commando raids, Vietnamese patrol boats fired on the ship. Bamford produces credible evidence that this incident was deliberately provoked by the U.S. military, which wanted something that would persuade Congress to declare war. "Body of Secrets" is filled with stories like this. The book is interesting to read, well-written and scrupulously documented. Eighty-one pages of references list reports, interviews, articles. I just wish I could get my hands on Bamford's files.

Maya Angelou reads from "The Heart of a Woman"