Add to ORKGThis article explains why shifts in the balance of power lead to war in some cases, but not in others. I argue that the declining states military strategy is the key determinant of whether power shifts will result in war or pass peacefully. If the decliner has a maneuver strategy, then war is likely; if it has an attrition strategy, the power shift will pass peacefully. I test the plausibility of my theory and three prominent alternatives by taking a sample of twelve power shifts among great powers over the period 1860-1945 and establishing correlations between the indicators used by all four theories and the incidence in each case of war or peace. This article finds that for the large majority of the examined cases, the decliners military ...