 Any successful theory of global legitimacy has to cover the following three issues. First, what are global governance institutions and in what ways can and should they be thought of as taking over roles from states or their governments? This is a question about the subject of global legitimacy (Hurrell and MacDonald 2012). Second, what is the legitimacy problem that such governance institutions face? And, third, how can they solve this problem of legitimacy and what are legitimacy criteria that apply to them? How, if at all, do these criteria differ from those that apply at the level of nation states?