Former Secretary of Defense, John S. McCain Distinguished Fellow
Dr. Mark T. Esper became the 27th Secretary of Defense in July 2019. As Defense Secretary, Esper was responsible for ensuring the United States’ national security, protecting the American people at home and abroad, and advancing the country’s interests globally. Prior to becoming Defense Secretary, Dr. Esper served as the 23d Secretary of the Army from November 2017 through June 2019. Currently, he serves as the John S. McCain Distinguished Fellow for the McCain Institute.