text: Well, the Christians  spent almost 500 years in the Crusades against the Muslims,  and it wasn't until after that that Martin Luther started questioning the Catholic Church.  
  
  The "protestants'  have split so many times since then that there are too many little groups to have a good war.  Of course, the Jews have always been a good target for all unhappy 'Christians' but they are alos too dispersed to make a good war.
  
  And socio-political movements like those in Northern Ireland have always liked to hang their desire for power on a religious hook.  I believe that is also part of the actual meaning of the Sunni-Shi'a conflicts over the centuries including the present day.