The United States Department of Defense (DoD) is the federal agency responsible for coordinating and supervising all agencies and functions related to national security and the military. Established in 1947, it oversees the U.S. Army, U.S. Navy, and U.S. Air Force, among other components. The DoD's primary mission is to protect the country and its interests through military readiness and strategic planning. The DoD is headquartered at the Pentagon in Arlington, Virginia. It plays a crucial role in formulating defense policies, managing military operations, and ensuring the safety of the nation. The department also works closely with international allies to promote global security and stability.