The 2013–2016 West Africa Ebola Epidemic is the largest outbreak of Ebola Virus Disease (Ebola) to date. By mid-2014, cases were escalating rapidly, and response actors in Sierra Leone were overwhelmed. Consequently, the British government announced Operation Gritrock, a bespoke military mission to support the country’s Ebola response alongside the national army. This study examined the origin, nature, and effect of this militarised support and the civil-military relationships that transpired. 110 in-depth interviews were conducted between 2017 and 2018. Perspectives were sought from a range of civilian and military Ebola Response Workers (ERWs) at the chiefdom, district, national, and international levels. Interviews were complemented by analysis of 21 key policy and operational documents not in the public domain obtained through the Freedom of Information Act of 2000. Analysis drew on neo-Durkheimian theory of organisations combined with inductive thematic exploration. Across respondent groupings, the militaries’ intervention was perceived to represent valuable and life-saving assistance, including for the establishment, operation, and leadership of the hierarchically organised National and District Ebola Response Centres. However, it was also found to result in various harms, including the marginalisation of some public institutions and local groups that were insufficiently included in the formal response. In turn, Sierra Leone was left somewhat vulnerable to future crises. This concurrent positive and negative effect—a paradox this thesis terms the ‘political economy of expedience’—is one in which all civilian and military ERWs were implicated. However, the militarised response also provides lessons for how hierarchical spaces need not be exclusionary ones. Indeed, this thesis ultimately finds that when organised with ‘conflict attenuation’ in mind, hierarchy and decentralisation—and therein, localisation and inclusivity—can be co-dependent and synergistic principles that, if applied robustly, could serve to mitigate the political economy of expedience paradox during future public health emergency responses.