Maybe not right now, but they WILL need aid from the very people they let down when they needed the Empire most. Hammerfell and Skyrim are perhaps the two most vauable people for the Empire to have on side, but the treaty destroyed both relationships and the Emperor was too foolish to see this.
Relationship with Skyrim is tensioned via Ulfric Stormcloak. Hammerfell while they are indeed valuable, can restore relations with the Empire far more easily than they would Skyrim. Hammerfell and Skyrim never get along.
I wouldn't be too quick to blame the Emperor, treaties aren't handled by the Emperors. The Elder Council wrote up the treaty, but to remove it they would need Titus II who is reluctant to involve himself where he's leading battle.
Titus II was dealt a crap hand to begin with, his actions during the Great War spared the Empire to fight another day.
He does, he's the general of the Fourth Legion, which was placed in Skyrim under his command during the Civil War. Legions are bolstered by auxilliries, not made up by them.
He isn't. Tullius is the Military Governor, he commands several 'Militia' Legions in Skyrim Also the "Fourth Legion" is false, as it was something written on wiki without anything to back it up. In-game or out of game, the Fourth Legion has never been mentioned.
In Skyrim there are no standard Legions, they all went south to the Aldmeri Dominion's border. Skyrim maintained a small garrison when Ulfric's rebellion struck, so 99% of their forces are locally recruited. Listening to their conversations they all speak of joining very recently.
If the Stormcloaks were fighting a normal Legion, it would be a very different story.
My point exactly. Every Imperial you speak too will sooner or later mention how the Empire is the only one keeping the Dominion out of Skyrim as in if they left Skyrim would instantly fall, when we know that isn't true, they are in fact the only reason the Thalmor can openly be in Skyrim and enforce the Concordat, whether that's to keep the Dominion on side for now or not the Empire is still using it's people to prolong it's self. The Northern regions of Tamriel would stand a much greater chance of defeating the Thalmor if they worked together, but neither of the regions apart from maybe High Rock have any faith left in the Empire at all.
The Thalmor don't require an open presence, to truly "push" them out of Skyrim. You need to defeat Summerset Isle. The Empire is keeping the Dominion out of Skyrim, should the Empire fall. There would be little keeping the Aldmeri Dominion to flood into other regions.
The Empire has a good chance with the Thalmor, because both use espionage and assassination. The Stormcloaks don't have anything to combat the Thalmor in that type of warfare. Skyrim is actually a very fragile place, should Ulfric die, it would be civil war once more.
"True, I may meet my end in a dark alley with a dagger in my back..." - Ulfric Stormcloak
The problem the Stormcloaks make is, instead of keeping one standing army. They plan to create nine, and every Jarl gets his/her own army. Looking at the Stormcloak Jarls, do you honestly believe they could elect someone else?
That may be true, but like I tried to explain before, without a legal reason to be in Skyrim any operation they wish to conduct will be insanely difficult and any intelligence they wish to pass on will be even harder without a legal system from The Summerset Isles to the North of Tamriel. The ONLY way to get to TSI from Skyrim is by Sea, or through Cyrodill by the road south out of Skyrim. I'm no expert but I'm sure it would be next to impossible to infiltrate one border.
They've been infiltrating the Empire for over a hundred and fifty years. You already come across one Nord working for the Thalmor, there will always be more. You should never underestimate the Thalmor. The Blades did and the Empire did.
People who do know about the Thalmor, can tell you it true. I think one NPC mentions "You can never be too paranoid when the Thalmor are concerned"
It isn't hard to get into Skyrim, there is an Altmer in Windhelm who mentions she came off the boat from Summerset Isle.
Then why in gods name do the Empire insist on fighting Skyrim instead of saying "Hey look guys, I know what we did was a dick move but look, we hate them too and we need you to invade with us". This is why I feel the Empire is being played or are just as idiotic as the Stormcloaks.
The Empire didn't want to get involved. The rebellion had been going on for years, the Empire only stepped in when Torygg was killed several months ago.
Ulfric killing Torygg and going into complete open rebellion, forces the Empire to step in. Due to the political situation of it all, it can cause a domino effect. If one ruler can get away with killing their liege and getting rewarded for it by an Empire who appears weak they couldn't even try to stop it. What about all the various other Lords in the provinces who go "Hey, I want a better castle, I want more land."
Ulfric won't make peace with the Empire, he's hated them ever since his father died. Look at it this way, majority of Ulfric's supporters are completely anti Empire. Would they support him if he made a deal with the Empire to get the throne?
The Thalmor are stirring up people against the Empire on purpose, because the Empire is getting close to being ready for war. Should talk to the Thalmor, they talk extremely bad about the Empire. I've seen Stormcloaks showing the quotes from Thalmor Justiciars in this thread, because they just eat up everything the Thalmor say.
To me, the Empire was planning ahead, they play all nice to the Thalmor. But with their other hand, they're setting themselves up for the next war. When the Legion retakes Riften, they mention they have a staging point into Morrowind just in case. The Imperials are covering their rear, the Stormcloaks haven't shown any real strategic sense other than "we're taking our entire army over to the Aldmeri Dominion!"
Riften's economy is actually booming right now from the production of Fish and Mead. Also the EETC being independent is very important, as like you say they are backed by Imperial coin but sooner or later the Emperor won't be able to afford to back the EETC if they hold just one province, so being mainly a mercentile group they won't show 'loyalty' so to speak but rather they will go where the coin is. Also Skyrim is a Tundra not a wasteland, many sources of food and natural materials are available and any trade that needs to be done can still happen without the support of the Empire, which like I keep trying to reiterate, only has one province and no say whatsoever on trading throughout Tamriel. The Empire simply doesn't have the strength to raise trade taxes and deny trading routes all together anymore.
Riften is actually extremely poor, as mentioned in conversations from the Jarl. The EETC has ports in every single province, they make money for the Empire. The EETC denied trade to half of Skyrim due to a few pirates. They're raising prices on Morrowind, most likely simply out of spite.
Skyrim is a harsh land, farming is hard work and a lot of the time crops apparently fail. With the only exception of Rorikstead which will always do well. Skyrim has a lot of resources, but they've always had allies or holdings in other provinces. Ulfric is taking Skyrim back to before the Empire, without expanding their holdings to include the fertile farmlands they once held.