I have been a Len Deighton fan for many years, and as well as his spy stories, I have been fascinated by his 20th Century Histories, which have clearly informed them. Blitzkrieg however was one book which had passed me by, so I was delighted to see it on offer, second hand, on Amazon.
Deighton's research and analytical skills are hugely impressive, but what brings this book alive are his novelist skills in integrating the "back story" of the events leading up to Dunkirk with the origins, thinking, approach and often stupidity, of all the sides involved in this conflict. Strongly recommended, particularly for those involved in implementing the current flawed defence review, and the procurement of armaments, whose approach, seems at times, to be harking back to the 1930s.
If the idea of "raw history" does not attract, then I recommend you try his wartime books such as Bomber, Goodbye Mickey Mouse, SS GB, and above all, Winter. Without realising it, you will learn a lot about 20th century history, whilst being swept along by the stories.