The role of international friendship in regional integration—be it as a factor encouraging it or as a by-product of it—tends to be overshadowed by (realist) assumptions of naked self-interest. This article aims to open up a space for friendship in the study of the regional integration, by exploring the structuration of a series of speech acts and institutional facts that can be interpreted as signs of engagement in, and proofs of, friendship. In doing this, it puts forward a new analytical perspective and methodological framework. The case studies chosen to illustrate the analysis—the Franco-German and the Argentine-Brazilian dyads—reflect the historical meaning of the experience of moving away from enmity/antagonism towards building relationships based on mutual trust, which put these dyads at the centre of regional integration processes.