With a view to providing contextual background for the Special Issue, this opening article analyses several dimensions of ‘The end of International Relations theory?’ It opens with a consideration of the status of different types of theory. Thereafter, we look at the proliferation of theories that has taken place since the emergence of the third/fourth debate. The coexistence and competition between an ever-greater number of theories begs the question: what kind of theoretical pluralism should IR scholars embrace? We offer a particular account of theoretical engagement that is preferable to the alternatives currently being practised: integrative pluralism. The article ends on a cautiously optimistic note: given the disciplinary competition that now exists in relation to explaining and understanding global social forces, International Relations may find resilience because it has become theory-led, theory-literate and theory-concerned