The political scientist who relies upon historiographic sources to propose and test hypotheses runs the risk of riling up not only her peers in the discipline, but also the historians upon whose work she must rely to provide the materials for these hypotheses. It was intellectually satisfying and stimulating to learn that my work has been read not only by scholars in ‘my’ discipline, but also by those in the discipline which made my own analysis possible, and I am grateful for Professor Hopkins' extensive comments. As Hopkins notes, there are differences in the orientation of the two disciplines: political science has as one of its central concerns ‘the state’, while historians are more interested ‘in charting changing relativities in international relations’. As a political scientist, I am indeed interested in identifying the factors which lead to such changes.