Operation Barbarossa and Germany’s Defeat in the East by David Stahel
This describes the initial stages (first few months) of the German invasion of the Soviet Union in 1941. It makes a very well reasoned case that despite their significant progress in this period the Germans were inevitably doomed to failure. Their inability to sustain anything like the necessary logistical support as they moved so deep into the Soviet Union was very damaging. Additionally, their inability to support the massive losses also ultimately led to failure.
It was a Christmas present.