Columbia subject headings:
European Union countries--Relations--United States.
National security--Europe.
National security--United States.
North Atlantic Treaty Organization.
United States--Relations--European Union countries.
Harvard subject headings:
European Union countries--Relations--United States.
National security--Europe
National security--United States
North Atlantic Treaty Organization
United States--Relations--European Union countries.
Princeton subject headings:
European Union countries--Relations--United States.
National security--Europe.
National security--United States.
North Atlantic Treaty Organization.
United States--Relations--European Union countries.