Which should I protect? Rome or Caesar?

If I were Brutus, and had to decide peace of Rome or Caesar, I would kill Caesar and protect the peace of Rome. Because the people like Cassius, and Casca aren't satisfied with Caesar's way of governing Rome, Rome wouldn't be peaceful anyway, because they might going to start a war. As it says in FYI Act One "Lean and Hungry Cassius," Cassius hates Caesar, and soon they might start a war in Rome, which wouldn't make Rome a peaceful place. So as a best friend of Caesar, Brutus have to kill him to make Rome a peaceful.
Also in FYI Act One, Caesar have a sickness. He isn't healthy, so somebody should become a new leader of Rome, because if Caesar kept leading Rome, he might not able to give best decision when some emergency happens.
From these reasons, I think Brutus should kill Caesar, and make Rome a peaceful place.