US Defense Department

The Department of Defense is a public safety agency that performs a variety of functions, such as war fighting, humanitarian aid, peacekeeping, disaster relief and homeland security. It contributes to homeland security through its military missions overseas, homeland defense and support to civil authorities. The department provides the defense support of civil authorities when directed to do so by the president and secretary of defense. The Department of Defense trains and equips the armed forces through its military departments, as well as maintains Marine Corps, Coast Guard And Unified Commanders. With a location in Indianapolis, it employs a work force more than 450,900 troops and civilians in over 160 countries in the world.