Large-scale military platform procurement is an essential but understudied component in policy and administrative studies. Procurement decisions in this area, which include major platforms and systems such as ships and aircraft, are very expensive and feature complex multi-actor and multi-year processes which can be highly conflictual. The extant administrative literature on the subject is of limited help: on the one hand, most procurement studies in public administration and public management focus on smaller, short-term, more routinized and less conflictual purchases. On the other hand, studies centred on military acquisitions tend to treat each major purchase as idiosyncratic. Hence, military procurement provides an excellent source of case studies to expand our knowledge and understanding of larger and more complex types of procurement processes. It allows us to draw lessons about successes and failures that will be relevant to similar expensive and large-scale purchases, such as railways, hydroelectric dams, highways and port development, while also drawing out the similarities and lessons for future defence purchases.