State-Building at What Cost? The Consequences of Military Control in Medieval China

A key challenge to state-building in conflict-prone societies is the proliferation of autonomous armed actors. As governments seek to enhance their monopoly over violence, consequences of military centralization deserve scholarly attention. We argue that centralization undermines state’s coercive capacity: by weakening the leaders of armed groups, it simultaneously erodes the military efficiency and discipline of these groups, which also serve as agents of coercion for the state. We leverage a centralization reform in China’s Tang Dynasty (618-907 CE) after a civil war, using unique data on soldier mutinies, rebellions by local generals, civilian uprisings, and battle outcomes. Difference-in-differences estimates reveal that centralization successfully reduced local generals’ rebellions, but led to increased soldier mutinies against the generals and more civilian uprisings. It also worsened battlefield performance. While research on state capacity has focused on its extractive and administrative dimensions, these findings deepen our understanding about another important aspect: the coercive dimension.