Have many relatives who were in the wars. Grew up with a neighbor who stormed the beach on D Day and another neighbor who was interred along with his family and lost everything. Had a great uncle pull a roman candle on D Day and shattered both legs landing in a swamp. He ended up several inches shorter after being put back together. Most never talked about it with those that weren't there. But in family reunion type gatherings it was obvious who fought and who didn't in the war as the vets would form their own group right away.

Best reads, IMO, are pre-US involvement in the war. Nobody knows exact numbers but it's estimated China lost up to 20 million and the USSR 23 million. My father worked with a guy who was in the german army on the Russian front. Pure hell. One tactic of the Russians was to send wave after wave at you trying to run out your ammo. In the rear they had sharpshooters ordered to kill anyone who retreated.