ABSTRACTWhy has the perennial idea of a permanent, individually recruited UN force never been realised? Scholars have responded to this question by interrogating the attributes of the various ideas but this only provides a partial answer. This article explores the latest proposal for a UN standing force – the UN Emergency Peace Service (UNEPS) – through the lens of a transnational advocacy network (TAN) and the external issues affecting its ability to put the idea on the UN’s agenda. It engages with social movement literature, and draws on interviews with those in the campaign to establish a UNEPS, participant observation, and analyses of primary and secondary sources. It argues that, in addition to contentions surrounding aspects of the UNEPS proposal, the failure to leverage the expertise of all network members and the lack of geographically diverse advocates, partly explain the inability of the TAN to achieve its goals. While there were some political opportunities, such as the support of influential allies and focusing events, an inhospitable political and normative climate, the lack of a state champion, UN body and journalists further contributed to the demise of the campaign.