Terrorism -- 21 September 11 Terrorist Attacks, 2001 11 Terrorists -- 8 Prevention 5 September 11 Terrorist Attacks, 2001 -- 5 Terrorism 5 War on terrorism, 2001- 4 more ... Child terrorists 3 Foreign relations 3 Foreign relations -- 3 Government policy -- 3 Influence 3 National security -- 3 Religious aspects -- 3 Terrorists 3 Anti-Americanism 2 History -- 2 Islam 2 Islam and state -- 2 Prevention -- 2 Security, International 2 Bombers (Terrorists) -- 1 Causes 1 Cold War 1 Computer network resources -- 1 Congresses 1 Congresses. -- 1 Directories 1 Directories. -- 1 Emergency, 1948-1960 1 less ...