Dan Caldwell, a senior adviser to U.S. Defense Secretary Pete Hegseth, has been placed on administrative leave and escorted from the Pentagon as part of an ongoing investigation into unauthorized disclosures of sensitive information. The specific nature of the alleged leaks has not been disclosed, and it remains unclear whether Caldwell underwent a polygraph test.
Caldwell, a former Marine Corps veteran, has been a close associate of Hegseth since their time at Concerned Veterans for America. He also served as Hegseth’s liaison in a private Signal messaging group used by top Trump administration officials to coordinate military actions, including strikes against Houthi militants in Yemen. The chat group gained attention after journalist Jeffrey Goldberg was inadvertently added.
The investigation into leaks was initiated following a March 21 memo from Hegseth’s chief of staff, Joe Kasper, which warned Pentagon personnel about unauthorized disclosures and indicated that individuals could face polygraph tests and potential criminal prosecution.
In addition to Caldwell, Darin Selnick, the Pentagon’s deputy chief of staff, has also been placed on administrative leave in connection with the probe. The investigation is part of a broader effort by the Trump administration to address leaks within the Department of Defense.