The Pentagon is reeling as Defense Secretary Pete Hegseth faces growing instability within his ranks following the sudden departure of his chief of staff – the fourth staffer exit amid the fallout of the disastrous Signal chat leak.

Joe Kasper, Hegseth’s top aide and longtime ally, is expected to leave his role in the coming days, according to a senior administration official, marking the latest in a string of high-level personnel shifts that have thrown the Department of Defense into a state of uncertainty.

The top-ranking official’s ‘planned’ departure comes on the heels of suspensions handed to Senior Advisor Dan Caldwell, Deputy Chief of Staff Darin Selnick and Colin Carroll, who serves as Chief of Staff to Deputy Defense Secretary Stephen Feinberg.

All four had been swept up in an internal investigation into possible leaks of sensitive government information.

At the center of the ongoing controversy is a Signal group chat – a secure messaging app known for its privacy protections – created by National Security Adviser Michael Waltz to coordinate US military responses to Houthi attacks in the Red Sea.

However, the group inadvertently included editor-in-chief of The Atlantic, Jeffrey Goldberg, raising immediate concerns over the exposure of sensitive and potentially classified information.

Hegseth and others shared detailed operational plans within the chat, including timelines and specifics about US military assets.

Defense Secretary Pete Hegseth (pictured) faces growing instability within his ranks, following the sudden departure of his chief of staff and an escalating scandal over a controversial Signal chat involving senior Trump-era officials

Joe Kasper (pictured), Hegseth’s top aide and longtime ally, is expected to leave his role in the coming days, according to a senior administration official

In response to the leak of sensitive and private intel, the Pentagon’s acting inspector general launched a review to determine whether Hegseth and his staff followed proper procedures when using private messaging platforms for official communication.

The review will reportedly also assess whether they adhered to classification rules and records retention protocols.

However, Politico reported that Kasper had requested an investigation into Pentagon leaks back in March. 

His request is said to have included military operational plans for the Panama Canal, a second carrier headed to the Red Sea, Elon Musk’s controversial department visit and a pause in the collection of intelligence for Ukraine.

Still, internal friction may have contributed to the current upheaval as one defense official told Politico: ‘Joe didn’t like those guys,’ referring to Caldwell and the other since-terminated officials. 

‘They just didn’t get along. It was a personality clash,’ the official, speaking on the condition of anonymity, said. 

With the exits of Kasper, Caldwell, Selnick and Carroll, Hegseth is now without a chief of staff, deputy chief of staff or senior adviser in his front office.

‘There’s a complete meltdown in the building,’ another senior official told Politico. 

The top-ranking official’s ‘planned’ departure comes on the heels of administrative suspensions handed to Senior Advisor Dan Caldwell, Deputy Chief of Staff Darin Selnick and Colin Carroll, who serves as Chief of Staff to Deputy Defense Secretary Stephen Feinberg

At the center of the ongoing controversy is a Signal group chat – a secure messaging app known for its privacy protections – created by National Security Adviser Michael Waltz to coordinate US military responses to Houthi attacks in the Red Sea

The Signal chat fallout has amplified criticism of Hegseth’s already embattled leadership, with some arguing it highlights a pattern of mismanagement. Pictured: The Pentagon in Washington DC

‘This really reflects on the secretary’s leadership. Pete Hegseth has surrounded himself with people who may not have his best interests at heart.’

The Signal chat fallout has amplified criticism of Hegseth’s already embattled leadership, with some arguing it highlights a pattern of mismanagement.

‘Everyone knew that Pete Hegseth did not possess the leadership qualities, background, or experience to be Secretary of Defense,’ Chris Meagher, who served as assistant Defense secretary for public affairs during the Biden administration, told the outlet.

‘Everything we’ve seen since then – the firing of several American heroes because of perceived lack of loyalty, the sloppiness of Signalgate, the complete lack of transparency, and now several political staff being shown the door – has only confirmed he doesn’t have what it takes to lead.’ 

The chaos follows the controversial removal of Joint Chiefs Chair Gen. C.Q. Brown and Chief of Naval Operations Adm. Lisa Franchetti earlier this year. 

‘There probably will be more chaos,’ a third defense official added. ‘It certainly reinforces the fear factor, awareness that no one’s job is safe.’ 

‘The front office has some really first-rate uniformed military staff, but there’s only so much they can pick up in an organization that big,’ a former Trump administration official said summing up the critical conflict. ‘That kind of dysfunction compounds.’