the capacity of an institution marked by the rigour of its hierarchy to make accessible to its personnel the margins of autonomy necessary for the engagement of frugal forms of technological research and development. Through an analysis centred on two case studies-a grenadelaunching pole and an oxygen mask for dogs-of innovation by and for Special Forces operatives, we highlight the difficulty, for the military institution, of making an 'innovation logic' coexist with an 'organisation logic' and articulating them.