The Secretary of Defense is the principal defense policy advisor to the President. Under the direction of the President, the Secretary exercises authority, direction, and control over the Department of Defense. The DoD uses geospatial technology to assist its mission of providing the military forces needed to deter war and to protect the security of the United States. Some of the key DoD organizations that use geospatial information and technology to support this homeland security and national preparedness include the National Guard Bureau (NGB), Northern Command (NORTHCOM), Global Positioning System Operations Center (GPSOC), NORTHCOM 543rd Geospatial Planning Cell (GPC), Joint Interagency Task Force North (JIATF North), Joint Force Headquarters National Capital Region (JFHQ-NCR), North American Aerospace Defense Command (NORAD), Southern Command (SOUTHCOM), Joint Interagency Task Force South (JIATF South), U.S. Special Operations Command (USSOCOM), U.S. Army Corps of Engineers (USACE), and the Multi-Agency Collaboration Environment (MACE).