• Dan Caldwell, adviser to Defense Secretary Pete Hegseth, placed on administrative leave amid a leak investigation.
• The leave follows a memo requesting an investigation into unauthorized disclosures of national security information.
• Both Caldwell and Deputy Chief of Staff Darin Selnick are under investigation for potentially compromising sensitive information.
• The Trump administration has emphasized efforts to prevent leaks and ensure accountability among defense officials.
• It's unclear if the investigation is related to an earlier Signal group chat involving military plans.

Dan Caldwell, a senior adviser to U.S. Defense Secretary Pete Hegseth, has been placed on administrative leave after being implicated in a probe concerning unauthorized disclosures at the Pentagon. An unidentified official confirmed that Caldwell's leave was prompted by allegations of an "unauthorized disclosure," although the specifics of the claims remain unclear according to reports from Reuters.

On March 21, Hegseth's chief of staff, Joe Kasper, issued a memo instructing the Pentagon to investigate recent leaks of national security information and proposed the possible use of polygraphs, indicating the seriousness of the situation, as detailed by Newsweek. The investigation aims to conclude with a report to Hegseth, detailing unauthorized disclosures within the department.

Additionally, reports confirm the suspension of Darin Selnick, Hegseth's deputy chief of staff, as part of the broader investigation concerning unauthorized disclosures. He was also escorted from the Pentagon on the same day as Caldwell, and both officials have previously been associated with the organization Concerned Veterans for America, which Hegseth led, according to India Times.

Caldwell, who served in the Marine Corps, has previously sparked controversy with his views suggesting a reduction of U.S. military presence in conflict areas, such as Iraq and Syria. His role as a key point of contact in discussions involving sensitive military strikes has also drawn scrutiny after a Signal group chat mistakenly included an editor from The Atlantic, as reported by HuffPost.

The ongoing investigation emphasizes a commitment within the Trump administration and the Pentagon to tighten controls over sensitive information disclosures, amid longstanding concerns over national security leaks and their implications for military operational security.