Flips and Flops: Alliance Defection in Great Power Competition

Abstract

Why do states sometimes betray their allies and “flip” to a rival state? Great powers compete not only directly, but also for the allegiances of other states. As evidenced by Italy’s betrayal of its Germanic allies during World War I or the American leveraging of the Sino-Soviet split during the Cold War, driving and exploiting divisions in a hostile alliance can have a momentous impact on the balance of power. If the advent of the nuclear age has made great power conflict a more costly and thus a less attractive means for achieving international goals, the realignment of one country’s disposition away from a rival can reap major benefits at both lower risk and substantially reduced cost. The dominant theories in the alliance literature suggest that alliance fluctuations are functions of threat perception. This dissertation suggests that external threats may motivate a state to shift alliances, but that threat alone cannot explain what enables a state to exit its current alliance and enter a new one. My research demonstrates that states flip when two specific variables are aligned: the state’s political regime is strongly cohesive and its existing alliance is weakly cohesive. Strong regime cohesion enables the state to flip alliances without domestic repercussions while weak alliance cohesion erases any institutional shackles that would maintain the alliance beyond the interests it served. Derived from an original database of alignment flips, I conduct four detailed case studies of prominent 20th century alliance flips. Given the challengers to the current vast American alliance system, alignment flips are likely to be an even more attractive proposition for American competitors in the years to come.