From the research I’ve done on this individual I’ve discovered that towards the later parts of the war a lot of Hitler’s decision making became more desperate and erratic. To be more specific I’m curious about:
Did Hitler’s early success in annexing/occupying/aligning central and western European countries give him a false sense of confidence?
When Hitler started to face setbacks on the Eastern Front, did this as far as we know harm his mental state?
As I understand he was a fan of using a lot of narcotics, did this change anything as the war went on?
Did Hitler initiate the Holocaust in 1941 purely because that was as parts of the USSR was occupied which in turn placed large Jewish populations under German jurisdiction, was it always his plan or did he just snap and take a more extreme turn? More than anything I’m just curious why he chose this time to begin the mass killings. Why not after Poland?
How did betrayals from Hitler’s allies throughout the war change him? The flight of Hess, the surrender of Italy and the Slovak Uprising are some examples I can think of.
This is my first post here so I hope I’ve formatted and written this correctly. Cheers.
I have found answers by /u/Georgy_K_Zhukov and /u/commiespaceinvader and /u/vonadler for Was Hitler a good strategist? that will be of interest to you.
Commiespaceinvader has also written about Hitler's drug use and about Hitler's role in the development of the Final Solution. These answers and more, e.g. "When did Hitler go crazy?" can also be found in Was there a "guy behind the guy" with Hitler?, including a helpful podcast episode about intentionalism and functionalism, two competing/complementing schools of thought about why the Holocaust happened.