In terms of security clearance, which agency is ultimately responsible for enforcing compliance?

The Department of Defense (DoD) is ultimately responsible for enforcing compliance with security clearance protocols. This agency oversees the majority of personnel security clearance processes, ensuring that all procedures align with established national security standards. The DoD governs how clearances are granted, maintained, and revoked, making it a central authority in this area.

While other agencies like the Information Security Oversight Office and the Department of Homeland Security play important roles in security policy and oversight, they do not have the same level of authority over the security clearance processes as the DoD. The White House, while influential in national security matters, primarily sets policy rather than enforcing compliance. Therefore, the DoD's direct involvement with personnel security clearance and compliance makes it the correct choice.