Alright now, where should I start.
I must express my general opinion first. After I will justify my opinion. I think Overy is wrong. However, when I challenge his opinion, I challenge the opinion of the general stream of western history writing, so it's risky. I'm doing it anyway.
So, I'll kick this off by stating - at the risk of sounding extreme - that I believe the old generation of history writing is trying to push Britain's naive actions (appeasement) regarding to Hitler onto everyone of his contemporaries. In this book, on Stalin. It looks to me like an attempt to justify the "gutlessness" of those times by generalizing it and simply drawing Hitler out of it, as if he was extremely different from other dictators, other leaders.
I am no Hitler fanatic, simply interested in the man in a historical point of view. And the more I read, the more I'm beginning to think he wasn't so awful as portrayed by us Europeans. His actions were so little different from those of Stalin, for example. Are we judging Hitler on partially false charges?
Overy has choosen his general line, which is that Hitler wanted war and Stalin only wanted to defend his country, and sticks to it without second thoughts. In fact, this is where I think the value of this book is diminished: on page 443 of this book Overy says that Stalin was o n l y being defensive and reactive. He mentions the possibility of Stalin's possibly aggressive plans in the 30s and the 40s and discards it the next sentence, stating simply that "the balance of evidence favors my idea". As if it couldn't be true that Stalin wanted communism in Europe.
Overy seems to ignore very important facts and very important evidence when drawing his conclusions. He for example fails to mention the aggressive nature of the armament produced by the soviets. Honestly, no man in his right sense would suggest that Stalin wanted to Defend his country with weapons unsuitable for defensive warfare, unusable in the USSR! I think Overy is being too one-sided, leaving out some major facts. This limits his views. And this was just one example.
I also think Overy uses quotes and other citations where they are not relevant (you know this if you know the context). For example, when he cites a speech held by Stalin in 1925, where Stalin pronounces that "the USSR shall have to participate in WWII but it shall only do it last to throw the decisive weight onto the scales, the weight that shall turn the scales." This does sound offensive. Overy however, only chose to mention the part where Stalin says that the USSR shall act last. This doesn't sound offensive as in the original speech, but rather cautious, hereby supporting Overy's thesis.
Of course the book has its value. If you are a high school student holding a speech on Stalin or Hitler, you'll be sure to get full marks by simply quoting this book. The thesis supported by Overy is what the academic Europeans hold in value. I w o u l d be critical however.
There is more to it than what this book tells you.