A monumental war history in German, which has just been completed after 30 years of work, explores a question that preoccupies modern Germans: why Nazi Germany fought on, defying all military logic, to the bitter end.

The government-funded military historians who researched the series are thoroughly anti-Nazi, but at the same time were curious about the strategy and mindset that drove their grandfathers' generation.

The findings can be set alongside existing histories of the US, British and Russian military efforts to complete the picture of what happened on the battlefield during the titanic 1939-1945 conflict.