Sir John Desmond Patrick Keegan, OBE, FRSL was a British military historian, lecturer and journalist. He published many works on the nature of combat between the 14th and 21st centuries concerning land, air, maritime and intelligence warfare as well as the psychology of battle.
One of my least favorite WWII books. It was difficult to read and I had a hard time picturing everything going on. The author bounced around several times to various battles and sieges, without reminding us who/what/where he is talking about. Once someone's name was mentioned, he assumed you would remember who it was.
It seemed like he listed city after city, army name after army name, general after general, and it didn't really have a point. They were able to get across some reasoning behind certain attacks/defensive strategies, etc, which was great, but the language was very difficult to understand. I had a hard time taking everything in.
If you're interested in Operation: Barbarossa, I would recommend a different book to help with your understanding. This book will only confuse you further!
These Ballantine books offer excellent military history of WWII. Compact and very readable, they are not all 5-star like Keegan's "Barbarossa," but none of them are bad.
Although Hitler had signed a non-aggression treaty with Russia before his invasion of Poland, his ultimate goal was world domination. Keegan has put together a historical account of Hitler's invasion of Russia which led to war on both the Eastern and Western fronts.
Another excellent introductory story from Ballatine Books. The reader is given just enough information to want to explore other works in an attempt to understand the magnitude of this campaign.