Government policy -- National security -- 7 Terrorism -- 6 War on Terrorism, 2001-2009 3 Intelligence service -- 2 Prevention -- 2 Prevention. -- 2 more ... September 11 Terrorist Attacks, 2001 2 Civil defense -- 1 Civil rights -- 1 Computer networks -- 1 Computer security -- 1 Defenses 1 Emergency management -- 1 Evaluation. -- 1 Foreign relations -- 1 Governmental investigations -- 1 Political violence -- 1 Politics and government -- 1 Security measures -- 1 Terrorism 1 Terrorists -- 1 Threats -- 1 United States -- 1 War on terrorism, 2001- 1 less ...