Alexander Velez-Green is the Chief of Staff and Senior Counselor to the Under Secretary of War for Policy. He is also performing the duties of the Assistant Secretary of War for International Security Affairs. Prior to that, he performed the duties of the Under Secretary of War for Policy from January to April 2025.

As part of his duties, Velez-Green was tasked by the Under Secretary to serve as the principal drafter of the 2026 National Defense Strategy, responsible for translating a more realistic and commonsense approach to U.S. foreign and defense policy into the Strategy’s framework, logic, and guidance. Velez-Green also led development and drafting of the 2025 Interim National Defense Strategic Guidance, strategy-focused elements of the FY27-31 Defense Planning Guidance, and the Department of War’s Review of AUKUS.

In addition, Velez-Green advises the Under Secretary on matters related to U.S. defense strategy and policy, including overall strategic guidance, contingency planning, global force management, current operations, and alliance management. He also oversees work by the Policy organization in these areas.

Previously, Velez-Green was a senior policy advisor at The Heritage Foundation, where he was the lead author of Heritage’s special report on U.S. defense strategy titled “The Prioritization Imperative: A Strategy to Defend America’s Interests in a More Dangerous World.”

Prior to Heritage, Velez-Green served as National Security Advisor to U.S. Senator Josh Hawley (R-Mo.). In this capacity, he staffed Senator Hawley on the Senate Armed Services Committee. Velez-Green was also the lead drafter of the COVID-19 Origin Act, which received unanimous support in Congress and was signed into law in March 2023.

Velez-Green has been an adjunct staff member at the RAND Corporation. He also worked in the defense practice at Systems Planning and Analysis, Inc., and at the Center for a New American Security. His work in the latter organizations focused on strengthening nuclear and conventional deterrence in Europe and the Indo-Pacific.

Velez-Green has published in The Washington Post, The National Interest, The American Conservative, National Review, Newsweek, Bulletin of the Atomic Scientists, War on the Rocks, Lawfare, Defense News, and Defense One, among others. He has also published with the Belfer Center for Science and International Affairs, Center for Strategic and International Studies, and Royal United Services Institute, and spoken regularly across the United States and Europe.

Velez-Green graduated cum laude from Harvard College. He is a novice mountaineer and has lived, studied, and traveled in more than forty countries, including a backpacking trip from Cairo to Cape Town.