Department of Defense (U.S.)

The U.S. Department of Defense (DoD) is the federal government agency responsible for national security and military operations. It oversees all branches of the U.S. armed forces—Army, Navy, Air Force, Marine Corps, and Space Force—and manages defense policy, strategy, research, and logistics. Its mission is to protect the United States from threats, ensure national security, and support international stability. The DoD operates complex military systems, collaborates with allies, and allocates resources to maintain readiness and technological advantage while providing support during emergencies and crises.