Understandings of cross-border university collaboration are often informed by a concept of internationalisation that privileges the rationales of university administrators. A case study of two asymmetric universities along the border of Mexico and the United States--one of the most active and problematic borders in the world--found that, rather than administrative rationales, the insecurities and desires of individual collaborators play a more prominent role in cross-border academic work. Through studying the interaction between two universities, this study found that social, cultural, historical, and economic contexts at national, institutional and individual levels condition cross-border collaboration. The effects of these contexts, however, are sometimes contradictory and can lead both to closer ties (hybridisation) and stronger divisions (bordering) between faculty and students in two geographically nearby and academically distant universities. (Contains 2 tables.)