Résumé
While a growing number of contributions rely on the concept of coopetition, they adopt very different, and sometimes contradictory, perspectives. Our article aims to lay a foundation for future research on coopetition by defining what can and cannot be categorized as coopetition. Building on a Lakatosian approach, we identify three assumptions that compose the "hard core" of coopetition as a research program. We argue that coopetition requires (1) simultaneous competition and cooperation; (2) an intense competition between partnering firms in critical markets, and (3) an intense cooperation between competing firms in critical activities or markets. In addition to the hard core, the Lakatosian approach enables us to highlight eight key debates that compose the "protective belt" of coopetition and that are represented as many research avenues. As coopetition becomes a trending research topic, defining its nature to lay its foundation is now more important than ever. This research thus contributes to a clear definition of what coopetition is and what it is not.