Social Theory of International Politics is in my view a major work in our field, fully deserving of this symposium in the Review of International Studies. Indeed, I think that Alexander Wendt's book is virtually certain to become a classic work on international relations theory, standard on graduate reading lists. Wendt's distinctive combination of scientific realism, holism, and what he calls ‘idealism’, will certainly spark much conversation and, it is to be hoped, a great deal of thought.