Prominent theories of state formation hold that states formed because of warfare and competition on the one hand, or the diffusion of organizational templates and practices through learning and emulation on the other. We propose that the two strands of theory can be linked to more accurately account for mechanisms of state formation. War, we argue, is an important source of social diffusion. War establishes contacts between political elites across borders, generates migratory flows, and establishes new economic networks. We examine the validity of the theory through a comparative case study of Nordic political units from the dawn of the Viking Age to the end of the High Middle Ages (CE 800–1300), finding that raids, settlements, and conquests by Norwegian and Danish rulers in England, Europe's most advanced kingdom, set in motion state formation processes in Norway and Denmark. In these cases, the winners emulated the losers.

著名的国家形成理论认为，国家的形成一方面是由于战争和竞争，另一方面是组织模板和实践通过学习和模仿传播的结果。我们建议可以将这两种理论联系起来，以更准确地解释国家形成的机制。我们认为，战争是社会扩散的重要来源。战争建立了跨国政治精英之间的联系，产生了移民流动，并建立了新的经济网络。我们通过对从维京时代初期到中世纪晚期（公元 800-1300 年）的北欧政治单位进行比较案例研究来检验该理论的有效性，发现挪威和丹麦的袭击、定居点和征服欧洲最先进王国英格兰的统治者，在挪威和丹麦启动国家形成过程。在这些情况下，赢家模仿输家。