A review by dimitribelgium
The Secret War: Spies, Codes and Guerrillas 1939-1945 by Max Hastings

3.0

With an overview of such a complex and shrouded subject, not every part will be equally interesting. Ineffective time-wasters of volunteer James Bonds aren't as sexy as the Enigma or their industrial scale US Navy counterparts.

Still, Hastings makes the best of it, with the benefit of the occasional declassified file or revealing memoir.