Columbia subject headings:
National security--United States.
Terrorism--United States.
United States--Armed Forces--Civic action.
Weapons of mass destruction.
Harvard subject headings:
National security--United States
Terrorism--United States
United States--Armed Forces--Civic action.
Weapons of mass destruction
Princeton subject headings:
National security--United States.
Terrorism--United States.
United States--Armed Forces--Civic action.
Weapons of mass destruction.