Secretary of Defense Pete Hegseth on Friday fired Navy Chief of Staff Jon Harrison, the latest move in a sweeping reorganization of the Pentagon’s leadership. 

Mr. Harrison was an official who helped implement the Trump administration’s defense agenda and had reported directly to Navy Secretary John Phelan.

A Department of Defense official confirmed Mr. Harrison’s dismissal in a statement, saying, “Jon Harrison will no longer serve as Chief of Staff to the Secretary of the Navy. We are grateful for his service to the Department.” The news was first reported by Politico.

Mr. Harrison’s removal comes just two days after the Senate confirmed Hung Cao, a former Navy officer and Republican Senate candidate, as the Navy undersecretary. This role, the second-most senior civilian position under Secretary Phelan, had been a point of internal conflict. 

Alongside Secretary Phelan, Mr. Harrison had reportedly worked to consolidate the Navy’s policy and budgeting offices and limit the influence of the undersecretary position that Mr. Cao is about to fill.

Reports indicate that Mr. Phelan and Mr. Harrison also reassigned several aides who had been designated to help onboard Mr. Cao and had planned to personally interview his future assistants to ensure their alignment with the secretary’s office.

Mr. Harrison’s nine-month tenure was marked by his support for Mr. Hegseth’s new military policies, which included canceling numerous outside contracts.

Before his role as chief of staff, Mr. Harrison was appointed by President Trump in 2020 to the United States Arctic Research Commission, where he served as chairman until the spring of 2021. The Arctic has become a significant area of interest for the administration, highlighted by efforts to explore oil and gas drilling in previously restricted areas.

Mr. Harrison is the latest official to be ousted in what has been described as a “house cleaning” by Mr. Hegseth. The shake-up has affected numerous high-ranking officials, particularly within the Navy. Other notable dismissals include the former chief of naval operations, Admiral Lisa Franchetti, and General Charles Q. Brown Jr., who was the first black chairman of the Joint Chiefs of Staff.

Mr. Hegseth, an Army veteran who attended both Princeton and Harvard, has been vocal about his agenda to reshape the military. In February, he dismissed the top military lawyers for the Army, Navy, and Air Force, saying they were not “well-suited” to provide legal advice. He also initiated the reassignment of 600 lawyers to serve as temporary immigration judges.

More recently, Mr. Hegseth has focused on the military’s culture and physical readiness. Speaking at Marine Corps Base Quantico earlier this week, he criticized the physical fitness standards of service members and leaders.

“Frankly, it’s tiring to look out at combat formations, or really any formation, and see fat troops,” the defense secretary told a group of generals. “Likewise, it’s completely unacceptable to see fat generals and admirals in the halls of the Pentagon. … It’s a bad look.”

He also called for an end to what he termed the “political softening” of the armed forces, including “identity months, DEI offices, dudes in dresses, no more climate change worship, no more division, distraction or gender delusion.”