History 24 Terrorism 21 Social conditions 16 Prevention 13 September 11 Terrorist Attacks, 2001 12 Economic conditions 8 War on Terrorism, 2001-2009 8 more ... Religious aspects 7 Genocide 5 Government policy 5 Islam 5 Psychological aspects 5 Social aspects 5 African Americans 4 Politics and government 4 Race relations 4 Violence 4 Children 3 Criminal justice, Administration of 3 Deaf 3 Death squads 3 Gun control 3 Intelligence service 3 Investments 3 National security 3 Women 3 Afghan War, 2001-2021 2 African American women 2 American Sign Language 2 Atrocities 2 less ...