Nations stay together when citizens share enough values and preferences and can communicate with each other. Homogeneity amongst people can be built with education, teaching a common language to facilitate communication, but also by brute force such as prohibiting local cultures. Democracies and non-democracies have different incentives when it comes to choosing how much and by what means to homogenize the population. We study and we compare both regimes in a model where the size of countries and the degree of active homogenization in endogenous. We also offer some historical discussions of cases which illustrate our theoretical results.