Northern donor policies relating to building a common future and building peaceful states and societies go to the heart of national and international security agendas. This article critiques the concept of commonality between donors and recipients and within recipient countries. It argues the policies are problematic from the perspective of security theorising, both in their mooted ‘commonality’ and in terms of the political intervention they imply. Historically, security has been competitive and founded on compromise rather than commonality, and the internal legitimacy of states has been contested domestically, rather than ‘built’ from outside. Using the example of the Democratic Republic of Congo, the article argues the ahistorical assumptions of these policies and the activities they license have entrenched specific forms of insecurity. There have been some returns to the donors and implementing partners but also costs, which had not been calculated, as lessons have not been drawn from past experiences.