The secretary of defense oversees the Defense Department and acts as the principal defense policy maker and advisor.

The Department of Defense is America's largest government agency. With our military tracing its roots back to pre-Revolutionary times, the department has grown and evolved with our nation. Our mission is to provide the military forces needed to deter war and ensure our nation's security. defense.gov

U.S. Army

U.S. Navy

The Department of Defense is America's largest government agency. With our military tracing its roots back to pre-Revolutionary times, the department has grown and evolved with our nation. Our mission is to provide the military forces needed to deter war and ensure our nation's security. $740.5 Billion National Defense Budget | 2.91 Million Service Members & Civilians | 4,800 Sites In Over 160 Countries
The Department of Defense is America's largest government agency. With our military tracing its roots back to pre-Revolutionary times, the department has grown and evolved with our nation. Our mission is to provide the military forces needed to deter war and ensure our nation's security. $740.5 Billion National Defense Budget | 2.91 Million Service Members & Civilians | 4,800 Sites In Over 160 Countries