Columbia subject headings:
International relations.
Petroleum industry and trade--Political aspects.
September 11 Terrorist Attacks, 2001--Causes.
September 11 Terrorist Attacks, 2001.
Terrorism--Political aspects.
Terrorism--Religious aspects--Islam.
United States--Foreign relations--2001-2009.
Harvard subject headings:
Conflict management.
September 11 Terrorist Attacks, 2001--Causes.
September 11 Terrorist Attacks, 2001.
Terrorism--Prevention
United States--Foreign relations--1989-
Princeton subject headings:
Conflict management.
September 11 Terrorist Attacks, 2001--Causes.
September 11 Terrorist Attacks, 2001.
Terrorism--Prevention.
United States--Foreign relations--1989-