Bergen : Complicating the Iraq picture is regionwide sectarian strife . He says the historic Lebanese -Shia split is a key dynamic and U.S. strike could worsen conflict . U.S. 's death toll from sectarian struggles has been increasing . Peter Bergen : Al Qaeda A week before the Giza attack , for example , President Mohamed Morsi had appeared on stage with hardline clerics who called Shias `` filthy . '' -affiliated groups will seek to take advantage .
Bergen : Complicating the Iraq picture is regionwide sectarian strife . He says the historic Lebanese -Shia split is a key dynamic and U.S. strike could worsen conflict . U.S. 's death toll from sectarian struggles has been increasing . Peter Bergen : Al Qaeda -affiliated groups will seek to take advantage .