Mallory Stewart

Mallory Stewart is a Senior Fellow at UNIDIR’s Weapons of Mass Destruction Programme. She is also the Chief Executive Officer of The Council on Strategic Risks, a nonprofit, non-partisan, security policy institute in Washington, DC. Her areas of expertise include weapons of mass destruction and outer space law and policy, and risk management regarding strategic stability and emerging and disruptive technologies.

From 2022-2025, she served as the Assistant Secretary for the Bureau of Arms Control, Deterrence and Stability in the U.S. Department of State. She joined the bureau after serving as the Senior Director for Arms Control, Disarmament and Nonproliferation at the National Security Council from January 2021. From 2015-2017, Mallory was Deputy Assistant Secretary of State for Emerging Security Challenges and Defense Policy in what was then called the Bureau of Arms Control, Verification and Compliance. Before her time in the Arms Control Bureau, Mallory served as an attorney adviser in the Department of State’s Office of the Legal Adviser. She joined the Legal Adviser’s Office in 2002, and in that role she worked on numerous legal issues related to nonproliferation, arms control, deterrence and US participation in international treaties.

Mallory holds a Bachelor of Arts degree from Harvard College and a Juris Doctor degree from Stanford Law School.