September 11 Terrorist Attacks, 2001 Terrorism 50 War on terrorism, 2001- 22 Influence 17 Foreign relations 14 World politics 13 Prevention 12 United States 12 Government policy 7 National security 7 Politics and government 7 Qaida (Organization) 6 History 5 Islam and politics 5 Islamic fundamentalism 5 New York (State) 5 Terrorists 5 World Trade Center (New York, N.Y.) 5 Intelligence service 4 Juvenile literature 4 Military policy 4 War on Terrorism, 2001- 4 Causes 3 Civil rights 3 Geopolitics 3 Great powers 3 Hegemony 3 Islam 3 Political aspects 3 Political violence 3