When that person is willing to make the decision that needs to be done and no one else wants too. Well not only that but also to have the integrity to stand behind that decision. It is hard to be the leader and even harder to be a good leader. Being a good leader goes hand in hand with picking and placing the right people for the right positions. I believe (as from my experiences in the military and in life in general) that if your support network is correct it is all but impossible to not be a good leader.