Causes Influence 2 Political aspects September 11 Terrorist Attacks, 2001 -- 2 Anti-Americanism 1 Foreign public opinion 1 Foreign relations -- 1 more ... Globalization -- 1 Intervent 1 Iraq War, 2003-2011 -- 1 Islamic fundamentalism -- 1 National characteristics, American 1 War on Terrorism, 2001-2009 -- 1 War on terrorism, 2001- 1 less ...