Alan is correct to point out that "leadership" is an earned attribution. It is an "emergent social property" and cannot be taken out of the social context. It is not the behaviour of the leader that is important but how that behaviour is interpreted by others. Thus "leadership" only exists in the minds of the followers (Attribution Theory). Looked at this way it explains why "leadership" is perceived differently in the military compared with commercial organisations or the social services. Alan uses the term "success" but is this an interpretation of the outside observer or team members?
Ultimately team members or even voters will "willingly and enthusiastically accept the authority of their leader" (a definition of leadership) if they perceive that their manager or leader delivers rewards to them. Different teams look for different rewards, be that financial or social or psychological thus "leadership" differs according
to the social situation (contingency model).
Leadership is not about being nice, it is not about so called "qualities" of the leader it is all about the experience and expectations of team members -it is an attribution- it is about delivering rewards. This is why in the world around us the only common characteristic of "leadership" is that such people have followers.