This'll be the final Holocaust post. For those who want futher fuhrer-ious discussion, convo button is to the side.
The way I look at the holocaust is as a progressively nihilistic "scorched earth" policy applied on people instead of resources. Specifically the people Hitler and his homedawgs held as eminently responsible for all of Germany's failures and misfortunes before and during the war.
Initially it seems like the jews in Poland were simply going to be hunger-plan'd out of existence, with those in Germany and western europe earmarked for eventual ethnic cleansing after the expected swift german victory, but when Germany invaded the soviets the Einsatzgrupen were formed and given orders to murder ever growing categories of jews in the occupied soviet territories, and once Germany's advance was halted and its desperate gamble in the east looked set to fail thats when plans for death camps started to take shape which were eventually rubber stamped by the Wannasee conference.
It should be remembered that Hitler and his close associates worldview of volk/race superseding all national loyalties and interests was not limited solely to germanic peoples. He saw this as true for all other races, including the Jews. Thus when shit started hitting the fan it was obviously because "the evil plutocratic jews in london/washington/moscow" had conspired to force their host nations into war against germany/refusing to lie down and die when invaded by germany, and thus to punish them punitive measures against all jews in europe, concluding with full blown genocide, was the obvious way to retaliate.
Especially since those Jews being murdered, from Bavarian artists to Polish farmers to Ukrainian street sweepers, from babies and children to crippled old people, were inherently complicit in the vast Jewish conspiracy by virtue of blood guilt and thus they had to pay the price for "the crimes of their race"
I'm going to try to tl;dr this and fail.
A lot of WWI veterans believed that Germany could have won, or at the very least gotten a better deal on the surrender, if they had kept going. One of the reasons they couldn't keep going is because Germany ran out of money, and the business/financial community wouldn't loan the Kaiser more money on war that was being lost.
Hating bankers is a popular past time for people who aren't bankers, and a disproportionate number of bankers were Jewish.
A lot of disgruntled WWI vets blamed a SPECIFIC SUBSET of Jews (Bankers) for the loss and the punishing terms of the treaty of Versailles.
This morphed into a general dislike of Jews in general, especially in the aftermath of WWI as members of the minority Jewish community were looked after by the disproportionate percentage of them that were less affected by the collapse of the german economy. (To put that a bit more clearly: Jews made up 2% of the population of Berlin, but owned 50% of the businesses and banks)
And eventually turned into stories of Jews actively sabotaging German efforts to force Germany to surrender at the end of WWI.
Hitler was one of these disgruntled WWI vets (its possible he simply parroted the argument and didn't really believe; but if he didn't believe he never broke kayfabe on the record). So Hitler did not like the Jews. Not the point of wanting them exterminated, but when he took over he wanted the traitorous, disloyal Jews out of his country, and those that wouldn't leave rounded up and watched so they couldn't sabotage Germany a second time.
Hitler was surrounded by people who DID have the sort of "kill them all" sort of attitude. Hitler had a real knack for identifying talent and delegating; so what happened is when he delegated things, he was almost certain to delegate them to someone who WOULD like to see the Jews as a people destroyed and wiped out.
Hitler also didn't like the Poles. This was, and remains, a popular European past time, so he was hardly out of step. He didn't view them as a race that was worth saving, and more or less planned to quietly exterminate ALL the Poles, not just the Jewish ones, by basically preventing them from having kids and letting them die out over a few generations, with a little bit of Ukrainian-style starvation tossed in there for good measure. (Which I mean was pretty much what he planned to do eventually with all non-Germanic people, planning to leave small 'reservations' for the non-germanic races he deemed worthy enough to save from total annilation, like the Anglos and the Rus-Russians)
Hitler's persecution of the Jews in Poland was made more rampant by the fact that was where a number of German jews had fled to, and knew what German occupation held for them, so became partisans, sealing the fate of all Jews in Poland to be regarded as partisans.
I suspect this mindset came about after the failure to take the caucuses became apparent and Hitler realised his ultimate gamble was about to start backfiring hard, and Hitler was probably just blue-sky thinking ways to salvage some form of half victory repeat of the brest litovsk treaty before the tsunami of soviet shit surged into germany.
That mindset was pre- and immediately post- Barbarossa. Well before it looked like things in the east had taken a nasty turn, and they were trying to manage the eastern european territory taken.
IIRC, the plan had been to take everything East of the Urals. Hitler debated leaving Stalin as the head of the USSR rump state or make him the administrator/governor of these captured territories of Western Russia, under the thought Stalin just liked power, would switch allegencies when he saw he'd have more power as a German vassal than a Soviet Dictator, and would be an effective vassal to keep the Russians in line.