While I do not agree that this is the single best one-volume treatment of World War Two available, I do agree it is a wonderful, eminently readable, and fascinating thematic approach that helps the reader look at the basic overarching themes to found in WWII. The introduction explaining how and why world wars became possible and attractive is worth the price of the book alone. Only Keegan could bring so much style, verve, and new perspective to such a widely covered subject as the Second World War. Therefore, understanding that the book is not an exhaustive and comprehensive history of the war on a battle by battle, theater by theater approach as one can find in other excellent one volume books such as Gerhard Weinberg's "A World At Arm" or Williamson Murray and Allan R. Millett's "A War To Be Won", it is still a singular tome with a unique and valuable perspective on the war that any self-respecting student of the war will not want to miss.
Also, given Mr. Keegan's mastery of the written word and his way with a phrase, this is a book one lets drag on as you read it slowly, stopping to think about what he has just written in a particular paragraph and what it means. This is indeed great stuff! The book is organized chronologically but devotes specific chapters in the general narrative to particular important factors influencing the progress and direction of the war effort, such as the nazi bombing campaigns, the Allied war air over Germany, war production, organized resistance in occupied countries, and the various types and relative successes associated with espionage.
Keegan's ability to marshal a stirring and articulate argument is unparalleled, and he relates the opposing forces' war strategies with an authority no one else can match. He also appreciates the many different levels of contribution to the overall war efforts ranging from unique leadership characteristics of specific individuals such as Montgomery, Patton, Eisenhower, and Marshall, but also pays attention to the massive contributions of ordinary soldiers, sailors, and war production civilians who made important efforts aiding ultimate victory. This is a very well-written and meticulously researched and documented book, and one I am glad to have on my World War Two bookshelf!