This review article situates the development of national and global food security discourses in their historical and political context. Geographical imaginations of ‘food security’ have shifted from a national to a global scale and, in some instances, back again. The dominant conceptualisation of food security, consolidated by the FAO Rome Summit on World Food Security, presents food security as a scientific problem rather than a political problem. ‘Food sovereignty’, on the other hand, is a counter-hegemonic discourse that questions the organisation of the current food system and calls for its transformation. From the global food security perspective, nation states are an obstacle to food security. Out-dated agricultural economies of the global south need to be improved through the adoption of biotechnology developed by scientists and corporations in the global north. Food sovereignty by contrast emphasises principles of rights and social justice over economics and technology. This article presents the different analyses of the problem and critically examines the internal assumptions of both discourses. We argue that the progression of the ‘food security’ debate will have clear geopolitical consequences with respect to the distribution of power in the global agri-food system and with regard to the autonomy of local communities and nation states.