Columbia subject headings:
Harvard subject headings:
National security--Germany
National security--United States
Security, International
Terrorism--Germany--Prevention.
Terrorism--Government policy--Germany.
Terrorism--Government policy--United States
Terrorism--United States--Prevention
Princeton subject headings:
Detention of persons--Germany.
Detention of persons--United States.
Internal security--Germany.
Internal security--United States.
National security--Germany.
National security--United States.
Terrorism--Germany.
United States. National Security Agency