Why do some countries engage in temporary wars and others in total war? In this paper, we develop a dynamic theory of concessions and war in order to shed light on this question. In our framework, an aggressive country can forcibly extract concessions from a non-aggressive country via war. Alternatively, it can avoid war and allow the non-aggressive country to make concessions on its own. Both countries suffer from limited commitment, and under peace, the non-aggressive country may receive a private shock which deems concessions too costly. We show that the realization of war sustains concessions along the equilibrium path. The aggressive country punishes failed concessions by requesting larger and larger concessions, and their failure eventually leads to a temporary war. The aggressive country forgives the non-aggressive country by re-engaging in peace after the war because of the coarseness of public information. In the long run, temporary wars can be sustained only if countries are patient, if the cost of war is large, and if cost of concessions is low. Otherwise, the aggressive country cannot continue to forgive the non-aggressive country, and countries converge to total war (permanent war).