Now this is a book that took me a little while to get into. It was actually an audio book, so it was much easier to let it continue then a normal book, but either way it was worth it. The book is about how Intelligence has factored into previous wars, and how countries have either managed to use it for their own success, or somehow failed even though the intelligence was there. It starts off with a lot of naval time battles back in the Napoleon era and how they used spies in the harbors to try and calculate where and when large fleets were located and when they had left. Since there was no radio, radar, etc., the data was often late, but nonetheless it was still useful. This part of the book was somewhat of a bore as it continually talked about ships at sea and the near misses that countries had while trying to find other ships.
The book eventually kicks into gear with more high tech intelligence when Morse code comes into play and how the British first start running wires across countries to increase the speed at which signals can be relayed. Of course then it comes down to encryption, and the book talks about the different styles of encryption and how to break them. The basics of encryption are to alter the original message into a non-readable format so that the enemy can’t read it, but have “key” so that the receiving party can decode it to read the original message. This “key” is the crux of all encryption. In the beginning, it used to be simple replacements of letters for other letters. However, in the english language, there are certain letters which appear more often than others, so if you are able to read the encrypted message and determine which letters are being used most often, then that is your first clue as to the algorithm being used since you can decipher what real letter it stands for. Obviously, as time progressed, the encryption methods became more robust, especially once the famous Enigma machine came out during WWII. This machine took years to decrypt as the key was ever changing. However, one of the main reasons it was decrypted was due to the laziness of the operators, and not necessarily from its design. Another cipher machine used was Purple. This machine was used by the Japanese prior to WWII, and was also eventually hacked.
The book ends with more modern day scenarios, especially with reference to the Al Quaeda group. Despite the vastness of technology, human intelligence has become the most important factor for this terrorist group. The book talks about spies, and double agents used during the Cold War, and actually references a few of them by name, one of which who falsified having 27 agents working under him, and was thus expensing 27 accounts to the governments. For obvious reasons, the book does not go into the more famous spies of today being used against terrorist organizations, but never doubt that they aren’t out there gathering intelligence to keep us safe.
In conclusion, if you are into war books, or books that deal with spies, ciphers, etc., then I’d have to recommend this book. John Keegan is one of the best story writers out there for this type of information.

“ If theres one thing Ive learned, its that life is one crushing defeat after another until you just wish Flanders was dead.