Power,Parity,and Place: Why Forgetting the Loss-of-Strength Gradient Misses the Relative Power Relationship

Students of international relations continue to debate the role of power as a cause of conflict. In particular, there exists no consensus about whether power parity or preponderance is more likely to trigger militarized disputes. Generally overlooked in this and related controversies is the question of where power is actually exercised. It is widely accepted that a state’s power declines with distance. This “loss-of-strength gradient” in turn must imply that the relative power of any combination of countries is not a constant, but rather varies spatially at different locations around the globe. Implementing this simple but as yet undocumented insight to the debate over the effects of relative power, we show that “proximate power”—i.e., power adjusted for the loss-of-strength imposed by distance—reveals a close relationship between parity and conflict onset. The finding conforms with the expectations of modern bargaining approaches to war, which emphasize the role uncertainty plays in precipitating military contests.