Columbia subject headings:
Border patrols--United States.
Coastal surveillance--United States.
Drug control--United States.
National security--United States.
Terrorism--Prevention--Government policy--United States.
Harvard subject headings:
Border patrols--United States
Coastal surveillance--United States.
Drug control--United States
National security--United States
Terrorism--Prevention--Government policy--United States
Princeton subject headings:
Border patrols--United States.
Coastal surveillance--United States.
Drug control--United States.
National security--United States.
Terrorism--Prevention--Government policy--United States.