User blog comment:Thedoucheinthenorth/Skyrim alignment charts-verdict?/@comment-4975504-20120801124732/@comment-5135631-20120803125947

His hold is listed in red on all maps, he gives you Imperial armour, all his guards carry Imperial swords, his brother, very much an Imperial representative, is allowed in a supposedly neutral court (I know this last example is quite poor since he is his brother, but if Balgruuf is as neutral as he claims to be then he should at least tell his brother not to spew his propoganda to people who will judge Balgruuf's claims to neutrality.) He is an Imperial representative. The Stormcloaks attacked him because they knew he was with the Empire, Balgruuf didn't side with the Empire because he was getting attacked by Stormcloaks, the Stormcloaks attacked him because he sided with the Empire. If Balgruuf had actually stayed truly neutral, Ulfric might have left him out of the war.

Despite everyone saying Ulfric craves the Throne, he rarely, if ever, talks about his rightful claim to the throne to you or Galmar. Elisif, however, mentions it in pretty much every second sentence, even after she has lost the war. Maybe he was always planning to insist on the Moot.