Mission: The mission of the Office of the Assistant Secretary of Defense for Homeland Defense and Global Security is to develop policy guidance; provide astute policy advice; and oversee planning, capability development, and operational implementation to assure warfighting and national security advantages in the mission areas of: Countering Weapons of Mass Destruction; Cyber; Space; Defense Continuity; Mission Assurance; Defense Support of Civil Authorities; and supervises Homeland Defense activities of the Department of Defense.