Si Horne

Colonel Si Horne was the Chief of the General Staff’s Visiting Fellow at the Royal United Services Institute until August 2024. An Army Emergency Medicine doctor, he has supported operations in Northern Ireland, Iraq, Afghanistan, Sierra Leone and South Sudan as well as serving as the Emergency Medicine lead for the Army. He was head of the Centre for Defence Engagement, building the Defence Medical Services’ capabilities in international engagement and capacity building. He has also undertaken system improvement in the NHS as Deputy Medical Director at the University Hospital NHS Trust, Plymouth. He was awarded an OBE in 2020.

He has published widely, from the management of mass casualties in high intensity conflict and disasters through to the ethics of infectious disease outbreaks. He holds a Global Health PhD from King’s, where he looked at the interfaces between military and civilian health services, from conflict and disaster relief through to peacebuilding. His current interests include the international use of health as a foreign policy tool, military contributions to national resilience and the challenges of the future battlefield.