Caroline Zier served as the Deputy Chief of Staff to Secretary of Defense Lloyd J. Austin, III. She was responsible for helping manage the Secretary of Defense’s executive staff and provided counsel and advice to the Secretary on all matters concerning the Department.

From February 2021 to June 2023, Ms. Zier was the Senior Advisor and Special Assistant to the Secretary of Defense with responsibility for policy and national security matters.

From June 2018 to February 2021, Ms. Zier was the Director for Global Posture within the Office of the Secretary of Defense for Policy. In this role, she led a team responsible for providing oversight and management of the forces, footprint, and agreements that support the Department of Defense’s global operations and activities.

From 2016 to 2018, Ms. Zier served as the Chief of Staff to the Assistant Secretary of Defense for Indo-Pacific Security Affairs. Prior to that assignment, Ms. Zier was the Special Assistant to the Deputy Under Secretary of Defense for Policy. Ms. Zier joined the Office of the Secretary of Defense for Policy in 2009, and has held several other positions in the organization.

Prior to her government service, Ms. Zier worked at Morgan Stanley in New York as an analyst. She graduated from Yale University with a Bachelor of Arts, and received a Master of Science in Foreign Service from Georgetown University.