People like Simon live in fantasy world that denies history and denies fact. The only thing Islamic terrorists want is the end of Western civilization and the death of everyone that won't submit to them. There is only the House of Islam and the House of War as anyone with even a cursory knowledge of Islam very well knows. Good luck with negotiating when they hold you down and cut your head off.
And yes, there will be more attacks. I am concerned about the "home run" major destructive event scenario but I'm even more concerned that the terrorist will abandon that effort and decide it's more productive to start blowing up shopping malls and shooting up school buses.