International Relations as an academic discipline is faced with three major convergent challenges: a historical challenge from the end of the Cold War and from new forms of internationalism and fragmentation; an institutional challenge from the growing preoccupation of other social sciences with the international; and a theoretical challenge both from these cognate disciplines and from within. Ranging widely over the discipline, Fred Halliday’s book powerfully reaffirms the specificity of International Relations and lays the basis for a long-overdue reformulation.