Although war is often portrayed as being antithetical to progress, Charles Tilly famously argued that wars laid the foundation for modern state building. In support of this claim, historical data shows that states obtain higher revenues from their citizens during times of conflict. Yet, conflict is also regularly viewed as being an impediment to progress due to the costs it imposes, making it difficult to assess its impact on state building. However, historical data also shows that states continue to reap the benefits of higher revenues in post-conflict periods when resources no longer need to be allocated to a conflict, thus suggesting the possibility that wars do in fact ‘make states.’ Evaluating the strength of this claim using historical data proves to be difficult given the existence of alternative explanations. Since wars do not occur randomly, it is difficult to separate the effects of war from the underlying conditions which precipitate it. We propose to close this gap in the existing literature by using a novel experimental approach to cleanly identify the effect of conflict on contributions to the state.