Contemporary combat casualty care has never been more sophisticated or effective, which is matched by an unprecedented level of clinical complexity. The management of this complexity has demanded the evolution of a more direct clinical leadership model in the field hospital: the Deployed Medical Director (DMD). The DMD has a central co-ordinating role in reducing the friction generated by individuals' unfamiliarity in a rapidly developing clinical environment that has diverged from the NHS; in cementing interoperability within a multinational medical treatment facility working at high intensity; and in maintaining and developing the highest clinical standards within the deployed trauma system. This article describes the evolution of the DMD role and illustrates the challenges through a series of vignettes. Particular emphasis is given to the organisational risk that the role carries through necessary ethical choices, the requirement to integrate multi-national cultural differences and the challenge of dealing with interpersonal frictions amongst senior staff.