Actually, the Muslims will probably continue to believe it no matter what, because they WANT to believe it. Now that Newsweek has done this, no retraction in the world is going to make them drop this. They are ignorant people manipulated by power-crazed fanatics.
However, I think Newsweek should suffer for this grossly negligent act, and should have to apologize and pay some kind of compensation. That's the only thing that might make them think twice next time.
The underlying theme that Newsweek is trying to perpetrate is that (some) Americans disrespect the Muslim religion and Muslims, and more particularly, that some of these are in positions of official power.
Is that theme accurate? Are there military people, guards, soldiers, etc. who disrespect the Muslim religion and Muslims? If so, the rioting Muslim masses will feel self-justified in their action.
Turn it around. Are there Muslims that disresepct the Christian religion and Christians? I see a religios war, and IMO, it was started by the Muslims.