Defense Secretary Pete Hegseth has dismissed Navy chief of staff Jon Harrison, a key aide assisting with his groundbreaking reshuffle of the Pentagon’s administration.

The abrupt removal of a committed senior figure at the Defense Department, now referred to as the Department of War, was confirmed by two defense officials and a former defense official in discussions with Politico.

The Pentagon later confirmed his departure, saying in a statement, ‘He will no longer serve as Chief of Staff to the Secretary of the Navy.’

‘We are grateful for his service to the Department,’ it added.

Harrison’s ouster comes as Hegseth has spent months cleaning house, with seemingly no one being off limits.

Several notable dismissals have affected the Navy, such as Admiral Lisa Franchetti, Chief of Naval Operations; Vice Admiral Nancy Lacore, Chief of the Navy Reserve; and Rear Admiral Milton Sands, head of Naval Special Warfare Command.

Possibly the most prominent termination was that of General Charles Q. Brown Jr., who was the first black chairman of the Joint Chiefs of Staff from May 2023 to February 2025.

Harrison, the recent figure to be removed during the Pentagon’s shake-up, had served for roughly nine months in a behind-the-scenes capacity, reporting to Navy Secretary John Phelan.

Working alongside Phelan, a significant donor to Trump lacking prior military experience before his appointment, Harrison aided in the merging of the Navy’s policy and budgeting divisions.

His changes also sought to limit the influence of the Navy Undersecretary, the number 2 to Phelan. 

That position is about to be filled by Hung Cao, a longtime Navy officer who was confirmed by the Senate on Wednesday.

Politico reported that Phelan and Harrison also reassigned a number of aides who were going to be tasked with helping Cao settle into the role.

The pair also planned to interview all future assistants to Cao to ensure they were aligned with the secretary’s office.

Cao, a Republican, previously ran for Senate in Virginia in 2024, losing to Democrat Tim Kaine. President Donald Trump nominated Cao for Navy Undersecretary in February. 

It remains unclear why Harrison departed from the service, but his fate has been shared by many under-the-radar personnel who serve under Hegseth.

Back in February, the former Fox News host and US Army soldier dismissed military lawyers, known as judge advocates general (JAGs), for the Army, the Navy and the Air Force.

When asked why he fired the JAGs — typically three-star military officers who advise commanders on the rule of law — he said they weren’t ‘well-suited’ to provide legal recommendations.

In September, The Washington Post reported that Hegseth began the process of reassigning 600 JAGs to serve as temporary immigration judges, a move meant to alleviate the backlog of immigration cases amid Trump’s mass deportation efforts.

Hegseth, on top of re-envisioning the military’s legal structure, is also on a crusade to make its top brass down to the infantry fighters adhere to new physical fitness standards.

Speaking at Marine Corps Base Quantico in Virginia on Tuesday, Hegseth told the generals who had convened from posts all over the globe that he was ‘tired of seeing fat troops’.

‘Frankly, it’s tiring to look out at combat formations, or really any formation, and see fat troops,’ he said. ‘Likewise, it’s completely unacceptable to see fat generals and admirals in the halls of the Pentagon leading commands around the country and the world.’

‘It’s a bad look. It is bad, and it’s not who we are,’ he continued.

Hegseth slammed the political softening of the armed forces, including concerns over bullying and hazing, and wokeness.

‘No more identity months, DEI offices, dudes in dresses, no more climate change worship, no more division, distraction or gender delusion, no more debris. I’ve said before and will say again, we are done with that s***,’ he said.