User blog comment:Thedoucheinthenorth/The Civil War - Why it is great/@comment-76.172.16.254-20121120131249/@comment-1600847-20121123030733

It's actually explained in Skyrim why Mede accepted the same terms he rejected at the start of the war: the provinces would have rebelled against him. But since the provinces were weary of a long war and desperate for peace, they accepted the terms.

Still, it would've been different had a Septim, not a Mede, been in control. That Septim would've marched right into Alinor and kicked some Thalmor ass. Alone. And he/she would've just glared at Ulfric, who would have promptly shat himself, curled up in a corner and cried. No one screwed with the Septimes for long!