Since the Rwandan Genocide in 1994, the border areas of Rwanda, Uganda, and the Democratic Republic of the Congo have been characterized by armed conflict and waves of cross-border migration, which have affected speakers’ realizations of the varieties of Kinyarwanda spoken in the area. The resulting recontextualized language use is best explored through a theoretical background of language ideologies and “border thinking.” With respect to Kinyarwanda, the fluid practice Kinyafranglais and the youth language Imvugo y’Umuhanda have emerged in relation to post-genocide language purification processes in Rwanda. In the ongoing conflict in DR Congo, secret metaphors in Kinyabwisha are used by Congolese armed groups when planning military operations, but they are also adopted by civilians when addressing delicate war-related topics. Pragmatic change in Rufumbira (Uganda) in the adjacent areas affect the realization of linguistic taboos, “sex talk,” and politeness strategies, which all deviate from patterns found across the border(s).