Dan Caldwell, a prominent adviser to U.S. Defense Secretary Pete Hegseth, was abruptly escorted out of the Pentagon on Tuesday amid a widening investigation into unauthorized disclosures of classified information, according to multiple defense officials. Caldwell’s removal marks the second high-ranking staff departure in connection with the ongoing probe into leaks that have rocked the Department of Defense in recent weeks.

A Sudden and High-Profile Ouster

Caldwell, who has served as a senior adviser to Secretary Hegseth and accompanied him to meetings with foreign officials, was placed on administrative leave after being identified as part of the inquiry. Security officers escorted him from the Pentagon, and his building access was immediately suspended pending further investigation. Pentagon officials have confirmed his removal but have declined to provide specifics about the nature or recipients of the alleged leak, citing the active status of the investigation.

Background and Influence

Though not as publicly recognized as other top Pentagon officials, Caldwell has been a key behind-the-scenes figure. His influence was highlighted in a recently leaked Signal messaging thread, published by The Atlantic, in which Hegseth described Caldwell as the primary liaison to the National Security Council during preparations for U.S. military action against Houthi targets in Yemen. Caldwell, a Marine Corps veteran who served in Iraq, previously worked at the conservative think tank Defense Priorities and at Concerned Veterans for America, where he first established his long-standing relationship with Hegseth.

Escalating Leak Concerns and Internal Crackdown

The Trump administration and Secretary Hegseth have made combating leaks a top priority at the Pentagon. In late March, Hegseth’s chief of staff, Joe Kasper, issued a memo directing the Pentagon’s director for defense intelligence to investigate recent unauthorized disclosures, including the potential use of polygraph examinations to identify the source. The memo warned that any findings identifying an individual responsible for a leak would be referred to law enforcement for possible prosecution.

Caldwell’s removal follows the earlier suspension of another senior Pentagon official, underscoring the seriousness with which the department is treating the breach. The specifics of the classified material involved and whether Caldwell’s alleged disclosures were made to journalists or other parties remain undisclosed.

Political and Strategic Implications

Caldwell’s ouster comes at a time of heightened sensitivity around national security information, especially as the Pentagon navigates complex military operations abroad and internal debates over U.S. commitments in Europe and the Middle East. Caldwell has been a vocal critic of large-scale military aid to Ukraine and has advocated for a reassessment of America’s global military posture, views that have sometimes put him at odds with mainstream defense policy circles.

What Comes Next

The Department of Defense has stated that the investigation is ongoing and has not ruled out further disciplinary action or legal referrals as more details emerge. A report on the findings and recommendations to strengthen information security is expected to be delivered to Secretary Hegseth upon the conclusion of the probe.

As the Pentagon works to contain the fallout, Caldwell’s sudden departure serves as a stark reminder of the high stakes and intense scrutiny surrounding the handling of classified information at the highest levels of the U.S. defense establishment.