Peter Bergen : Violence against U.S. over film is part of a pattern of incidents . He says Christian and Muslim extremists have incited deadly protests for years . Score: 7 In several cases , the words of political leaders have helped spark violence .
Peter Bergen : Violence against U.S. over film is part of a pattern of incidents . He says Christian and Muslim extremists have incited deadly protests for years . Bergen : In several cases , the words of political leaders have helped spark violence .