State collapse is the catastrophic breakdown of a sovereign state's institutional apparatus, resulting in the inability to sustain a monopoly on the legitimate use of force.
During periods of state collapse, a provisional government may be formed, particularly where whatever circumstances have caused the first stages of state collapse have resulted in a coup d'état. Regimes attempting to avert state collapse may become increasingly violent and paranoid, resulting in civil society actors and local leaders losing trust in the ability of the central government to exercise effective control and choosing to defend their interests militarily. Neighboring states or great powers may interfere politically, sometime supporting rebel groups. As a result of the collapse of the central government's ability to effectuate economic regulation and taxation, the informal economy becomes dominant, resulting in declining government resources and a vicious cycle of reduction in state capacity.