Ronald Lewin was a British military historian, radio producer and publishing editor who has wrote several books on World War II and several of the WWII commanders like Lieut-General Vyvyan Pope, Montgomery and Rommel.
Slight, but very well written, this book outlines what author Lewin identifies as the biggest mistakes Hitler made during WWII. Some are military, some pertain to domestic policies. Examples of the former include such things as his failure to focus on a single Soviet target, inadequate support of the Afrika Corps, failing to immediately invade England, etc. Examples of the latter include, especially, German racial policies, not only as applied to the Jews, but also as applied to minorities in the Soviet Union, many of whom were initially supportive of German occupation. Rather than coming off as some sort of genius, Hitler comes across as a narrow-minded narcissist, his successes oft being the result more of fortuity (f.i. the conquest of France) than of planning.
This was rather complicated to me in terms of military strategy. It argues that ultimately Hitler’s ego led him to great delusions and unrealistic goals. I consider it outdated and almost too neutral (another characteristic of outdated historiography). Definitely thought-provoking!