Balance-of-power theory has endured in the study of international relations because it can explain a great deal. When newly powerful states emerge on the world scene, other states sense threats and form counterbalancing alliances. But the empirical record has varied widely. Britain and France responded weakly to Germany's rise before the two world wars, whereas the Western democracies united effectively to balance against the Soviet Union after 1947. To explain these variations, Papayoanou investigates the economic relations between major powers. Status quo states are most likely to cooperate and balance against a rising power if they have strong economic ties with each other but not with the adversary. When economic ties with the adversary are extensive, however, a balancing strategy is difficult to sustain. There are few surprises here, but the book nicely attempts to integrate economic variables into grand strategy. Papayoanou also warns that dangerous security consequences arise if a country forges deep economic ties with potential adversaries, but he fails to examine the possibility that those ties might actually transform the rival state.