Terrorism Prevention 36 History 13 Terrorists 12 Congresses 10 Encyclopedias 7 Government policy 7 International cooperation 7 Islam 6 National security 6 Psychological aspects 6 Religious aspects 6 Politics and government 5 Social aspects 5 World politics 5 Civil rights 4 Law and legislation 4 United States 4 War on terrorism, 2001- 4 Biography 3 Counterinsurgency 3 Democracy 3 Emergency management 3 Political violence 3 Psychology 3 Security, International 3 War (International law) 3 Weapons of mass destruction 3 Foreign relations 2 Globalization 2