The Road to War by R. J. Overy
Linked with a BBC series, this book sets out to ask, without resort to hindsight, why the world's greatest powers were at war 50 years ago. It looks at Hitler's assumption that his invasion of Poland would be unopposed and his plans for a "war of great proportions" in the 60s, and aims to recapture the concerns, anxieties and prejudices of the statesmen of the 30s and the people they led. Richard Overy has also written "The Air War", "Goering: The Iron Man", and "The Nazi Economic Recovery: 1932-38". Andrew Wheatcroft has also written "World Atlas of Revolutions" and "Who's Who in Military History".