The Pope is not the symbolic leader of Christiandom and even most Islamics know there are plenty of different branches that oppose him. They all know also that the Greek Church and Latin Church are different.
You fail to grasp the symbolic status that the Pope holds, as leader of the Christian West. To think that a Baptist or Methodist is unaffected by what the Pope does is as naive as those "blue staters" who can't understand that Islam hates ALL of the West.
To put it bluntly, an Islamic attack on the Vatican would be an attack on all Christians, not just Catholics.
Islamics have deep memories.
SD