The civil war literature considers violence as a decay of the state since it destroys life, infrastructure, and the economy. This article argues that civil war is not only a process of state decay, but also a process of state formation. The article examines when and what kinds of variables of civil war can create a new state. Presenting a successful secessionist war, the liberation war of Bangladesh, the article argues that three factors such as capability of political mobilization, international/regional military intervention, and geography mutually determine whether war will create a state or not. Bengali rebels, known as „Muktibahini‟- Liberation Force, carried out a successful secessionist war because these three conditions mutually helped them. It concluded that if the war gets an optimum result within a relatively short time, war might be a process for the beginning of state-building.