A good leader is one who can recognize not only recognize potential, but is also able to put that potential into motion. For example, it is not enough for a leader to recognize that creating an alliance would benefit many nations, they also need the resolve to put that vision into action.
Another important component of an effective leader is the ability to admit when they are wrong. I think we can all agree that no matter how awesome a leader may be, at one point, they will screw up. If they project ignorance to their faults, it benefits no one.