Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Not a how-to manual

While Allen Dulles played a pivotal role in the US intelligence service, especially as head of the CIA, his book is not a tell-all revelation of the inner workings of a spy agency. It is however a great history of the cold war told from the perspective of a spymaster. He slips in some lingo like "dead letter box", but does not really get into the nitty gritty. He covers most of the already public spy stories. If you are studying the period of history from WWII to 1965 this book is a great read with an important perspective.