Peter, I don't think stable is the right word in the 1,000 year life of Islam. I agree with you that there have been a number of high moments in Islamic Civilisation (as Bernard Lewis has all but made clear to any interested reader), but the fruits of that high culture are not the ones we a likely going to experience in the 21st Century. Rather, I suspect there is so much pent-up animosity against the West that is itself rooted much like a "fifth column"-to use an old communist adage-within the western world, that this is the most likely enemy within our midst for whom to be on the lookout.

What I meant by "stable" is that unlike communism, Islam as a political system has lasted in many countries for over 1500 years.
While Islamic civilization has contributed much (astronomy, mathematics, etc.) to world civilization, they are at this time in history barbarians at our gates and because of our insane leftist immigration policies a dangerous fifth column as well.
The West has abandoned Christianity and every form of traditional morality and the sad effects of this new liberal thinking can be seen in Canada more than anywhere else. The biggest problem that this decadence has caused is our ever declining birthrate which if it continues will assure the death of our civilization and the triumph of Islam, possibly in the very near future.