Michael Mann's Sources of Social Power has been widely acclaimed as one of the classic works of contemporary sociology. In this related book he focuses on three of the four sources of power by examining the close inter- relationship between states (mostly modern states), war and the economy (mostly capitalist economies and class relations) and showing how an overall theory of any of these must involve consideration of them all. Social theory has concentrated on the relations of capitalism, social classes and the state within the individual nation-state, either neglecting international relations, militarism and war or seeking to explain them largely in terms of capitalism and class structure. These elegant and stimulating studies provide a necessary corrective to such biases and offer a fresh agenda for historical sociology.