Thinking about the contemporary political situation; where the reputation of Israel, and the United states (over a period of years, granted), have deteriorated. One aspect of a leadership change is a change in the face of the state. By a change of leader, there is a change of responsibility, by having parties, and different leaders, we can attribute, blame and praise initiatives and actions of states where they are respectfully due.
Long-term leaderships, or those life-term offices of the likes of dictators, do not have that priviledge. A change of leadership, is, in many respects, a change of agency.