How and to what extent do states influence the level of democracy and autocracy in other states? We argue that states exist internationally in dependence networks with each other and that those networks provide pathways for influence on a state’s domestic institutions. For any given state, a dependence network is a set of partner states with whom it regularly engages in exchanges of valued goods, where those exchanges would be costly to break. We find that an index of three such networks–trade, security and shared international organization membership–significantly influences the domestic political institutions in a given state. These changes are substantively large in the long run, similar in size to regional and global levels of democracy. State capabilities figure heavily in our network measures, thus emphasizing the role of power in the diffusion of domestic political institutions. We also find that network-influenced change works both ways: states can become more autocratic or more democratic.