• health security;
  • infectious disease;
  • medicalisation;
  • pandemic;
  • securitisation

How is the rise of global health security transforming contemporary practices of security? To date the literature on global health security has sought to trace how the securitisation of global health is affecting the governance of diseases in the international system; yet no-one has analysed – conversely – how the practices of security also begin subtly to change when they become concerned with a growing number of contemporary health issues. This article identifies three such changes. First, health security debates endow our understandings of security and insecurity in contemporary world politics with an important medical dimension. Second, the rise of global health security enables a range of medical and public health experts to play a greater role in the formulation and analysis of contemporary security policy. Finally, health security debates have also encouraged attempts to secure populations through recourse to a growing array of pharmacological interventions and new medical countermeasures. Drawing upon a rich literature in medical sociology, these three transformations in the contemporary practice of security collectively constitute the ‘medicalisation of security’. This novel perspective on the rise of global health security also reveals new limitations inherent in the emerging health–security interface – limitations associated not so much with the processes of ‘securitisation’ already noted in the global health literature, but rather with wider social processes of ‘medicalisation’. Awareness of the additional limitations renders the threat of a future pandemic even more serious than is commonly thought.