All Ulfric is doing is tearing Skyrim apart. If the Empire doesn't make this decsion to side with the Thalmor, they'll wage war against Skyrim and the damage will be even worse than Ulfric's mad quest for power-which is all he would gain out of this war, besides free worship of the Nord's 'favorite' God. Now, I personally hate the Thalmor. They have no reason for their actions and they are just pure evil, but they did decide to ban worship of Talos and now the Empire has no choice but to take their side. Eventually, the Empire will regain their right to worship their own god in their own land freely. Ulfric's actions are just plain stupid and unjust. He only seeks the gain of power and domination-something that does not come easy in Skyrim.