In a similar vein, This...
http://www.amazon.co.uk/Classified-Secrecy-State-Modern-Britain/dp/1107000998/ref=sr_1_1?ie=UTF8&qid=1368782380&sr=8-1&keywords=classified
...is quite interesting, not just on military matters. I'm still reading it, so will post my thoughts on it when I'm finished.
Bit academic for me, 20% of the page count is references and footnotes, which will meet with Phil's approval.
Chris