In the main arms-producing countries, Ministries of Defence are looking for alternative ways to acquire defence capabilities. Over the past two decades, several reform projects have been experimented to go beyond the model inherited from the Cold War, but they did not succeed in delivering expected results. One may wonder whether such defence acquisition systems correspond to their core mission: supplying boots on the ground with adequate capacities. The research agenda and reforms programmes are biased since they focus mainly on “how” to procure. While reforming existing mechanisms seems to fail or to deliver well below expectations, one may wonder in fact whether the true question should concern “why” and “what” to buy with regard to military needs but also the place that technology takes in conceiving defence capabilities.