Courtney Stewart

Courtney Stewart is a nonresident senior fellow in the Indo-Pacific Security Initiative at the Atlantic Council’s Scowcroft Center for Strategy and Security.

She is also the deputy director of the Defence Strategy Program at the Australian Strategic Policy Institute (ASPI). She is a senior defense and security professional with over twenty years of experience across the US and Australian Departments of Defense, think tanks, and the defense industry. Her areas of expertise include deterrence, defense strategy, Indo-Pacific geopolitics, military posture, and the US–Australia alliance. Her current work focuses on advancing new coalition-based approaches to deterrence in the Indo-Pacific region, strengthening Australia’s national defense strategy, and contributing to major defense initiatives shaping the future of force posture, capability delivery, and regional security cooperation.

Before joining ASPI, Stewart held senior advisory roles in the Australian Department of Defence, including at the Advanced Strategic Capabilities Accelerator and Army Headquarters. From 2015 to 2018, she served as the US Department of Defense’s policy exchange officer to the Australian Strategic Policy Division. In the Pentagon, she held roles including country director for Korea, senior advisor for preparedness policy, and member of the 2010 Nuclear Posture Review staff. She was the lead author and chief US negotiator of the 2013 US–ROK Tailored Deterrence Strategy Against North Korean Nuclear and Other WMD Threats—the first codified extended deterrence strategy with any US ally. She helped establish the US–ROK Extended Deterrence Policy Committee Working Group and the original US–Japan Extended Deterrence Dialogue. Her contributions were recognized with a US Secretary of Defense Medal for Exceptional Civilian Service in 2015. Earlier in her career, she worked at the US Department of Energy’s National Nuclear Security Administration and held research roles at the International Institute for Strategic Studies and Harvard University’s Managing the Atom Project.

She holds an MA in science and security from King’s College London (with merit), and a BA in political science and history from the University of California, Los Angeles, where she graduated with highest departmental honors.