In a rapidly developing situation within the Department of Defense, three senior aides to U.S. Defense Secretary Pete Hegseth have been placed on administrative leave amid an ongoing investigation into leaks of sensitive national security information. The officials—Dan Caldwell, Darin Selnick, and Colin Carroll—are suspended following concerns about unauthorized disclosures connected to high-level decision-making and classified operations.
The investigation stems from a March 21 directive issued by Hegseth’s chief of staff, Joe Kasper, warning staff that any disclosure of sensitive materials could result in polygraph testing and immediate disciplinary action. The probe has since expanded, targeting a network of internal communications that allegedly revealed plans and operations not authorized for public release.
Dan Caldwell, a Marine Corps veteran and former senior adviser at the think tank Defense Priorities, had been a close national security adviser to Hegseth. Caldwell is known for his opposition to prolonged foreign interventions and had input into recent Pentagon planning on counterterror operations in Yemen and Syria. Darin Selnick, a retired Air Force officer, was leading personnel and readiness policy initiatives. Colin Carroll, formerly of defense-tech firm Anduril, served as chief of staff to Deputy Defense Secretary Stephen Feinberg and held oversight authority over emerging technology projects.
Their suspensions come amid significant leadership turnover under Secretary Hegseth’s tenure, which began in January 2025 under the Trump administration’s second term. The administration has vowed to eliminate leaks and realign the Pentagon’s leadership, resulting in the resignation of several officials and the departure of the Defense Digital Service team, which claims it was marginalized under the new chain of command.
Notably, former Pentagon press secretary John Ullyot also resigned last week following an internal reshuffle that limited his access and authority. These high-profile exits suggest internal discord over the department’s direction and mounting concerns regarding transparency and control over sensitive operations.
Governor Pete Hegseth has not yet commented publicly on the suspensions but is reportedly cooperating with the Inspector General’s Office, which is now overseeing the investigation. Legal experts indicate that administrative leave is a precautionary measure pending further findings, though it signals the seriousness of the allegations.
The outcome of the probe could have major implications for operational security, internal oversight, and personnel retention at the Pentagon. As of now, no formal charges have been announced, and the investigation remains active.
Source Links:
https://www.reuters.com/world/us/pentagon-leak-probe-expands-two-more-officials-put-leave-2025-04-16
https://www.businessinsider.com/pentagon-staffers-are-dropping-left-and-right-heres-why-2025-4
https://apnews.com/article/d5306e0441dacae1a0d03c871be265bb
https://www.politico.com/news/2025/04/16/top-pentagon-official-resigns-00295381
https://www.axios.com/2025/04/17/pentagon-official-john-ullyot-resign-defense-department
https://apnews.com/article/344d480e47cf4c04e0b2c510bd333b02
https://www.youtube.com/watch?v=GuPE4yOcoXs
