U.S Department of Defense（下架中）

The Department of Defense is an executive branch department of the federal government of the United States charged with coordinating and supervising all agencies and functions of the government concerned directly with national security and the United States Armed Forces. The Department is also the largest employer in the world, with 1.3 million active duty servicemen and women Adding to the total is over 1.8 million National Guardsmen and Reservists from the four services, bringing the total to just over 3.1 million employees. It is headquartered at the Pentagon in Arlington, Virginia, just outside of Washington, D.C.