Hegemonic shocks and patterns of secession

Studies of secession typically focus on domestic factors that produce independence movements, such as the role of ethnic divides or the concentration of material resources. But motivations for secession are also linked to broader changes in the international system. This article examines the links between great power shocks and global patterns of secession. We argue that abrupt great power shocks, marked by the rise and fall of powerful states, trigger waves of secessionism by temporarily weakening metropoles and facilitating the diffusion of independence movements. These movements, however, often stumble when the global shock passes and local conditions like institutional capacity or the strength of the metropole regain importance. Using a comprehensive dataset of secessionist movements between 1900 and 2011, we find that great power shocks are closely linked with bursts of secessionist activity. Consistent with expectations, we also find that secessionist attempts in the wake of great power transitions are not more likely to succeed. Overall, the results suggest that sudden great power shocks play an important and under-examined role in the timing and success of secessionist movements.