Olivia Maese

The Department of Defense (DoD), established in 1947 through the National Security Act, serves as the United States' premier federal agency for coordinating and supervising all agencies and functions related to national security and the armed forces. It unified the previously separate War Department and Navy Department under a single cabinet-level secretary, streamlining command for the Army, Navy (including the Marine Corps), and newly created Air Force. Throughout the Cold War, the DoD was central to organizing the nation's strategic deterrence and global military operations, adapting to new threats and technologies. In the 21st century, the DoD continues to evolve, leading efforts in counterterrorism, cyber defense, and the modernization of U.S. military capabilities worldwide.