Derek Chollet, counselor of the State Department, will join the Department of Defense in July to serve as chief of staff.
In a statement published Monday, Defense Secretary and three-time Wash100 awardee Lloyd Austin said Chollet “is one of the most distinguished, far-sighted, and skillful national-security practitioners of his generation, and I am grateful to him for taking on this key assignment at such an important moment.”
Chollet will return to the Pentagon, where he served as assistant secretary of defense for international security affairs from 2012 to 2015.
His government career included time as special assistant to the president and senior director for strategic planning on the National Security Council and principal deputy director of the State Department’s policy planning staff.
Before moving to the State Department, he was executive vice president and senior adviser for security and defense policy at the German Marshall Fund of the United States.
Secretary of State Antony Blinken appointed Tom Sullivan, deputy chief of staff for policy, as the department’s next counselor.
“Tom has an unmatched depth of knowledge about how national security policy is formulated and implemented, one that he brings to bear every day on behalf of the American people,” Blinken, a previous Wash100 awardee, said in a statement.