Dan Caldwell is a national security expert and U.S. Marine Corps veteran who served from approximately 2005 to 2009, including an assignment to the Marine Corps Presidential Support Program at Camp David and a deployment to Iraq with 2nd Battalion, 1st Marines for Operation Iraqi Freedom in Al Anbar and Ninawa provinces. He graduated cum laude from Arizona State University in 2011 with degrees in Asian History and Political Science. His career includes roles as a staffer for U.S. Representative David Schweikert (R-AZ) from 2011 to 2013, focusing on veterans and defense issues; various positions at Concerned Veterans for America (CVA), including Legislative Director and Director of Policy (2013–Oct 2017), then Executive Director (2017–Feb 2025); lobbyist for Americans for Prosperity (overlapping with his CVA tenure); Vice President of Foreign Policy at Stand Together (post-CVA, pre-2025); Public Policy Advisor at Defense Priorities; former senior adviser to U.S. Secretary of Defense Pete Hegseth (Feb 2025–Apr 2025); and currently Senior Adviser in the Office of the Director of National Intelligence (ODNI) (Mar 2026–present). He has ties to conservative advocacy groups, including right-leaning veterans' organizations and the Koch network, and Arizona connections, splitting time between Arizona and Washington, D.C. Caldwell was involved in the 2025 Signalgate Scandal as Hegseth's point person in a Signal group chat discussing U.S. military strike plans against Houthi militants in Yemen; leaks prompted a Pentagon investigation, leading to his placement on leave (Apr 15, 2025), escort out, and termination (Apr 2025). He and colleagues (Colin Carroll, Darin Selnick) denied accusations of leaking classified information in a joint statement, calling them baseless slander; the investigation was ongoing as of mid-2025 with no charges filed.