Research on English Medium Instruction (EMI) in Higher Education (HE) has tended to have a technicist orientation, examining for example how it is implemented and the challenges it has encountered. Much less critical attention has been given to the rationales that language policy makers and other stakeholders offer for introducing EMI - the drivers may be reported (e.g. Rose et al., 2020, in China; Galloway & Sahan, 2021, in Vietnam and Thailand) but they are rarely questioned. Here, we focus on these rationales, using data from a research project which monitored the spread of EMI through Indonesian HE. Managers at 24 institutions were surveyed along with 281 lecturers who taught their subject in the medium of English at 41 universities. In the stakeholders' responses, we identified four common sense assumptions (Gramsci, 1971) about English and its role in Indonesia that often underlay their justifications for introducing EMI. We also noted some signs of resistance to EMI which demand further empirical investigation. This case reminds us that public language policy should be based on careful analysis of needs at national and institutional levels.