Terrorism -- 28 Terrorism 6 September 11 Terrorist Attacks, 2001 5 Prevention. -- 4 War on Terrorism, 2001-2009 4 Foreign relations -- 3 Islam 3 more ... Religious aspects -- 3 Terrorists 3 Terrorists -- 3 Emergency management -- 2 Islamic fundamentalism 2 Politics and government -- 2 Psychological aspects 2 Radicalism -- 2 War on terrorism, 2001- 2 Anti-Americanism 1 Biological warfare 1 Bioterrorism 1 Chemical warfare 1 Church and state -- 1 Citizen participation. -- 1 Civil rights -- 1 Criminology 1 Democracy -- 1 Emergency communication system -- 1 Globalization 1 Government policy -- 1 Hate crimes -- 1 Hijacking of aircraft -- 1 less ...