Back in the mid-1990s the United Nations Secretary-General Boutros Boutros-Ghali observed that securing the humanitarian space was ‘one of the most significant challenges facing the humanitarian community’ (Boutros-Ghali 1995: 172). In response to these challenges, CARE Canada and the University of Toronto’s Program on Conflict Management and Negotiation in 1999 offered what was then regarded as a ‘modest proposal’: humanitarian non-governmental organizations (NGOs) might rely upon private security for their protection (Bryans et al. 1999: 31, 33–7). Today, NGOs routinely engage private military and security companies (PMSCs) as they operate in increasingly ‘crowded’ environments including states following whole-of-government (WOG) engagements. Certainly, the challenges involved in securing the humanitarian space have evolved in part because of the developed world’s engagement in weak states following the events of 11 September 2001, and NGOs’ interaction with PMSCs is arguably both a cause and a response to these still ongoing and morphing challenges.