Bolton selected Fleitz to serve as his NSC Chief of Staff , replacing Keith Kellogg .
Fleitz had previously served as Bolton 's Chief of Staff at the State Department during the Presidency of George W. Bush .
Bolton selected Fleitz to serve as Fleitz 's NSC Chief of Staff , replacing Keith Kellogg .
Fleitz had previously served as Bolton 's Chief of Staff at the State Department during the Presidency of George W. Bush .