When you think about it more, that the Rebels were the ones who started the war? Who took up arms against the government while it was still technically democratic or semi-democratic, still had the elected representatives in the Senate? Albeit with the Emperor steadily increasing in power over the Senate and doing away with it soon after the Rebellion started.
You could argue that the construction of the Death Star was an aggressive enough act, against the government's own population, that it really did cause or force the Rebellion to emerge against the government.
You could argue that the construction of the Death Star was an aggressive enough act, against the government's own population, that it really did cause or force the Rebellion to emerge against the government.