There are "muslimes" and "muslimes". The differences between their sects are not smaller than between Baptists and Catholics, sometimes they are larger.
You should never underestimate your opponent. And you should always try to understand him.
"One who knows the enemy and knows himself will not be in danger in a hundred battles. One who does not know the enemy but knows himself will sometimes win, sometimes lose. One who does not know the enemy and does not know himself will be in danger in every battle."
(Sun-tzu, The Art of War, chapter III )
I am all for understanding in the name of destroying them, but nothing more.