Terrorism -- 13 September 11 Terrorist Attacks, 2001 7 Government policy -- 6 War on terrorism, 2001- 5 War on Terrorism, 2001-2009 3 Intelligence service -- 2 Islam 2 more ... Jihad 2 National security -- 2 Prevention. -- 2 Religious aspects -- 2 Terrorists 2 Afghan War, 2001- -- 1 Anti-Americanism 1 Armed Forces -- 1 Biography -- 1 Evaluation. -- 1 Forecasting. -- 1 Foreign relations -- 1 Governmental investigations -- 1 Hijacking of aircraft -- 1 Islamic fundamentalism 1 Islamic fundamentalism -- 1 Nuclear terrorism -- 1 Political violence -- 1 Press coverage -- 1 Social networks 1 Terrorism 1 Terrorists -- 1 War correspondents -- 1 less ...