Which department is responsible for overseeing national defense in the U.S.?

The Department of Defense is specifically tasked with overseeing all aspects of national defense in the United States. This includes the management of the military forces, defense policy, and the strategic deployment of assets to protect the nation. The Department of Defense is comprised of various branches of the military (including the Army, Navy, Air Force, and Marine Corps) and works in collaboration with intelligence, logistics, and planning to ensure national security.

In contrast, the Department of Justice focuses on enforcing federal laws, preventing crime, and ensuring fair administration of justice, rather than managing military and defense matters. The Department of Homeland Security primarily deals with protecting the nation from domestic threats, such as terrorism and natural disasters, but does not oversee military defense strategies. Similarly, the Central Intelligence Agency is involved in intelligence gathering and analysis, which supports national security but is not responsible for the direct management or oversight of national defense operations.