So what do you suggest we do with the spiritually-vacant mush-headed Americans that convert to islam?
Depends. Do they convert to all three parts? Or just the religious part?
It has not yet happened that I am aware of, but in theory it is possible, although not likely.
If they embrace the political and Taliban aspects of islam, then they, too, die.
Next question?
"Let 'em try it! THEY WILL DIE!"