It's also completely possible that one of their articles ticked off Osama and/or Saddam, certainly at least Saddam (and I'd assume Osama as well) has been ridiculed in that paper.
Despite terrorists like Osama and Bin Laden pretending to be "religious", they are nothing but childish egomaniacs and would not be above attacking a paper for printing something bad against them.
Any known Enquirer/Sun stories on Osama prior to 9/11? Did they perhaps cover his intimate relations with sheep?
I heard some talk a few days ago that there had been an article in (I believe) the Enquirer a few months ago ridiculing Osama and the size (or lack of size) of his male private parts.