"Inside the Nazi War Machine" by Bevin Alexander I just finished. He's a respected author and the book focuses on the destruction of the allied armies in 1940 by the brilliance of three German generals, Manstein, Guderian, and Rommel. The three of them creating a new form of warfare, often while disobeying orders, and the position of strength it put the new German Empire in.
Which Hitler promptly blew. He blew it by not destroying the British at Dunkirk and he blew it by not properly outfitting the Africa Corp and paying attention to the Mediterranean. He was obsessed with his idiotic racial theories and his desire for living space in Russian and the destruction of communism.
The book is almost entirely based on the French campaign but it does connect the dots on its implications on Later events.