This is going to be a very long post.
The Imperials are not “invaders” but the rightful government. Ulfric postures as the champion of Talos, but Talos as a mortal is the one who founded the very Empire Ulfric seeks to destroy! Keep that in mind as you go through what I wrote about the pro-Empire Nords’ attitude to Talos.
By the point of TES V: Skyrim, the Skyrim province has been a willing part of the Empire for centuries, and though the Empire is weakened, the treaty Ulfric rails about was the only way to keep the Aldmeri Dominion from destroying all of the Empire, Skyrim included. So, the screaming by Ulfric that the Empire “dishonored” everybody is BS because if the Empire hadn’t signed the treaty and banned Talos worship, everybody would have been destroyed. This is a very very thinly veiled comparison to the Treaty of Versailles, by which the liberal but weak Weimar Germany government ended World War I. The Versailles treaty “dishonored” Germany, and that was what Blankler screamed about the Treaty of Versailles all day long, and that was his pretext for power just as the ban of Talos worship was Ulfric’s pretext for power, but Germany had no choice but to accept it just as the Empire had no choice but to accept it.
What do I mean by “the same as Skyrim’s Empire” is, if you look at the Empire’s side of things, every Nord on the side of the Empire is against the ban of Talos worship and secretly worships Talos. Jarl Elisif, whose husband Torygg Ulfric murdered and whom the Empire supports in opposition to Ulfric quietly asks you to place Torygg’s family war horn at a shrine of Talos because she herself could not publicly do it. Legate Rikke, the Nord Legate leading the charge against Ulfric is likewise a Talos worshipper: she sometimes says “Talos be with you” to you, and when you kill Ulfric, she says “Talos guide you” to the corpse, which General Tullius wtf’s about. If you side with the Empire in the very start and go with Hadvar and meet Alvor in Riverwood, both of them admit that Talos worship is very important. Put plainly, Ulfric screaming about the ban of Talos worship = Blankler screaming about the Treaty of Versailles. Nobody in Germany was for the Treaty of Versailles, they had to bear it because there was no other choice.
So, again, Blankler screamed about outsider forces using the Treaty of Versailles to blank up Germany just as Ulfric screamed about non-Nords using the ban on Talos worship to blank up Skyrim. So, the ban on Talos worship being a pretext for power is about Ulfric wanting to be High King. Just as the Versailles treaty was a pretext for power for Blankler to take control of Germany. “Outsiders have dishonored and blanked us” was the marshalling call with both men.
Both Ulfric and Blankler are far-right racist extremists. Ulfric hates all non-Nords, wants them thrown out of the province, and treats them like garbage; in Windhelm, the Dark Elves and Argonians are second class citizens, and although Ulfric will fight for the Nords of his hold, when non-Nords are attacked he doesn’t care at all and lets literally anything happen to them. Talk to Brunwolf Free-Winter and he explains this. Of course, Blankler treated all non-Germans and “undesirable” Germans like inferior beings, not just Jews but gypsies, liberals, etc. This horrible, murderous treatment is what made it a World War and made Germany dishonored for real when it ended.
Blankler’s ideology was “might makes right” and “the strong deserve to get everything, no apologies.” Ulfric’s rallying cry is that the Empire has made Nords weak and by “drinking the Empire’s milk” the master race has turned to rubbish. Both Ulfric and Blankler believe that “true” Nords/Germans must be strong. There is also the extremely easy connection of Elder Scrolls Nords being Northern hardy Aryans: valuing strength and loving battle, and Nords are invariably powerful physically and are often blonde haired and blue eyed.
Both Blankler and Ulfric agitated for many years without getting much support. Both had a personal army of thugs as backing. Then, the Versailles Treaty/ban on Talos worship finally gave Blankler/Ulfric the visibility and rise to power they wanted.
Both Blankler and Ulfric use war as impetus for their personal ambition. The Europeans wanted peace and tried to appease Blankler, but he wanted war. Likewise, Ulfric wasn’t removed right away despite his views. It was when he murdered Torygg that the Empire could no longer ignore what he was doing and went to war with him, which is exactly what he wanted. Same as the invasion of Poland by Blankler being the final straw that Britain and France could not ignore.
Blankler’s speaking style was extremely charismatic but his views were animalistic and simplistic and focused on strength as justification for its methods. Ulfric is pretty much the same. The honorable but cranky Jarl Balgruuf the Greater describes Ulfric as a “bloodthirsty and dangerous man,” and this before Ulfric attacks his hold.
The Empire in Skyrim is cosmopolitan and liberal, but a bit decadent and weak. The Weimar government that preceded Blankler’s Third Reich was literally identical. So, in both cases, you’ve got an inclusive, liberal but decadent and weak government standing against a hard-right, racist, might-makes-right strongman.
I might have repeated some things, but I think you get the idea. I just hope I don’t get banned for the comparison like last time.