Terrorism -- Prevention. -- 27 Government policy -- 24 Foreign relations -- 20 War on Terrorism, 2001-2009 17 Prevention -- 16 National security -- 14 more ... September 11 Terrorist Attacks, 2001 13 Islam 11 Religious aspects -- 11 Terrorism 9 Politics and government -- 8 Terrorists -- 8 Prevention 7 Civil defense -- 6 History -- 6 Islamic fundamentalism 6 Jihad 6 Intelligence service -- 5 Islamic fundamentalism -- 5 Psychological aspects 5 Security measures 5 War on terrorism, 2001- 5 Civil rights -- 4 Emergency management -- 4 Political aspects 4 Political aspects -- 4 Politics and government 4 September 11 Terrorist Attacks, 2001 -- 4 Aeronautics, Commercial -- 3 less ...