>>43416
>He was certainly an optimist.
You can't win a war if you doubt yourself. Both sides have to believe in all of their hearts they are right and they'll win, and whatever others say (the enemy and the inner opposition) are lies, propaganda, pessimism, failing moral. If you start lament that you'll fail, it will paralyze you, preventing you from what needs to be done. It is very hard to do stuff when you consciously know that you might be wrong but you do it anyway out of "necessity", it would be very tempting to just give up, while the other has no such doubts, and no scruples to act against you - at that moment you lost.
Imagine if the Allies had believed the German propaganda.
This is also true for many things in life, for the average weekdays of the individuals too.

>Soviet manpower pool was much large
He mentions at one point that the Soviet had almost 200 million people. As for the Germans, he calculates that the task of gearing for total war is so large that it effects 100 million people directly (larger Germany) and another 100 million indirectly (rest of the European nations). So he supposed an even pool with the Soviet drained heavily and the German largely untouched.
I dunno how he hoped that the rest of Europe can be motivated to make the sacrifice - especially the French.
Just the usual miscalculations. Although considering that since then historians gave widely differing numbers for the participating troops in just all of the battles that was fought, similarly with the losses, no wonder the contemporary reports could have been misleading (especially if you won't believe what the other side writes).
Example. Glantz - who is considered a leading historian of the Eastern Front - says in an essay of his (2001): "2.5 million Red Army troops defeated over 1 million Germans at Kursk", while Wikipedia notes 1,9 million vs 800 thousand soldiers, citing a book by Glantz & House (2004)...