This book introduces a Theory of Global Democracy as a tool to implement the capacity to study today's International Relations through new lenses, different from those of the main theories of this field, that are Neo-realism, Liberalism, ""English School"", and Centre/Periphery. The principal concern of this new Theory is the difference albeit the opposition between the national dimension and the international dimension of democracy. Based on a philosophical research about the theories of democracy, the book investigates, through an analysis of historical and current events, what is wrong, but implicit, in the national theories of democracy.