Now what you just said...is wild speculation. Not to mention uncharacteristic of the Empire. If the Skyrim follows the Stormcloaks...they WILL cut off ties with the empire. And thus they will be far poorer for it. Whilst they keep the Empire they are stronger then otherwise. That's really all I have left to say on it for everything else has already been said.
It's not wild speculation at all. It's already been stated that the other nations are losing faith in the Empire and that it's exactly what the Thalmor wanted. Hammerfell wants nothing to do with the Empire and that is common knowledge. Nice try though.
Black Marsh left the Empire, Elsweyr left the Empire, Alinor cut off all ties with the Empire, Pyandonea decided to merge with the Aldmeri Dominion instead of the Empire, Titus Mede II turned his back on Hammerfell, who in turn labled the Empire as cowards and backstabbers. It's common knowledge that public opinion about the Empire from the other nations has decreased over the years. Even Skyrim is iffy about the Empire.
Far from wild speculation. It can all be found in the lore. Point is, if the other nations thought the Empire was still a competent establishment, the alliance wouldn't be in disarray at this point.