This book is about Bletchley Park, and the WW2 code-breaking efforts (Enigma, Lorentz, etc.). It was a present from someone who knows I have an intrest in this area. I was a bit apprehensive that it might have been a bit of a noddy introduction book, but actually it's set of chapters written by people who really do know what they're talking about, partly 'cos about half of them were present at Bletchley during the war!
If anything, it goes too far the other way, with slightly opaque explanations, and a fair amount of detailed reminiscing that doesn't help with the big picture. As there are so many authors, though, including a few who are very good at bringing it all together, it all eventually links up, and you get an impressive view of how it all worked. Just as when reading The Prize you think the war was fundamentally won on the management of oil, reading this you'll think the fundamental factor was intelligence! Oh, I'm so glad I'm not a historian, having to properly integrate and make sense of this.
One of the best things about the book is that it fits Bletchley into the pre- and post-war world, as so many other books ignore this angle. Christopher Andrew contributed a acouple of chapters, and one of the points he makes it that the importance of sigint in WW2 is now understood, but historians for the most part have ignored how sigint affected the history of the second half of the twentieth century (on the rather dull grounds that most historians don't take into account things that have been deliberately hidden!).
One fact that I think is so wonderful that it's worth repeating here is that, thanks to our code-breaking ability, we knew that in the middle of the war, every German agent in Britain had been turned into a double agent, and Germany hadn't the faintest. Marvellous.
Anyway, is this book any good? It's not a good first book on the subject. The descriptions of cryptanalysis are sufficiently terse as to require their own reverse engineering, and lot is tedious detail. If you can get past all this, well, yess, it's actually rather interesting.