Pentagon adviser removed during internal investigation into leaks

Dan Caldwell, a senior adviser to US Defense Secretary Pete Hegseth, was escorted out of the Pentagon on Tuesday and placed on administrative leave amid an internal probe into information leaks at the Department of Defense, a US official told Reuters.

According to the source, who requested anonymity, Caldwell was linked to a leak and removed from duty due to “an unauthorized disclosure,” as investigations continue.

The move comes amid a broader effort by the Trump administration to tighten its grip on internal leaks. On March 21, Hegseth’s chief of staff, Joe Kasper, issued a memo calling for an investigation into recent unauthorized disclosures involving sensitive national security matters. The memo also raised the possibility of using polygraph tests, although it remains unclear whether Caldwell was subjected to one.

Not tied to other high-profile Pentagon removals

Caldwell’s removal is not connected to other major dismissals under Hegseth’s leadership, which has already seen the ousting of the chairman of the Joint Chiefs of Staff, the head of US Cyber Command, and the Navy’s top admiral.

Who is Dan Caldwell?

Dan Caldwell has held a key advisory role within the Pentagon. A Marine Corps veteran who served in Iraq, he acted as a main point of contact for the National Security Council, particularly during planning for strikes against the Houthis in Yemen. 

His name was mentioned in a leaked Signal message that was reported by The Atlantic.