Question: who is right ulfric or the empire?
Answer: First of all, killing Ulfric Stormcloak and stopping the rebellion. Second, trying to get the two sides to call a truce and start focusing on the real enemy. Either side could do the latter, but only the Imperials can do the former. So while they may not be “right”, they are at least more “right” than the Stormcloaks.