In this article I discuss language policies in Uruguay regarding bilingualism in the Brazilian-Uruguayan border during the period of military dictatorship (1973-1985). In particular, I study linguistic reports produced by the Ministerio de Educación y Cultura (1980) and the Academia Nacional de Letras (1982) on this subject. The research contains a historical and sociolinguistic review, a discussion on purism and nationalism and an analysis of these reports as language planning tools, as well as propaganda media to legitimate authority. The institutional reports defended Spanish as a symbol of national identity and monolingual education as a tool to achieve their goals. The differences between these reports and linguistic research of the period are also discussed.