Oh, I don't know about that. History has shown us that whenever the population if Islam increases, they end up slaughtering themselves shortly after the period of slaughtering infidels.
This is because the treasure they steal during the slaughter of infidels is spent, the productive societies they invade slowly begin to fail as the dhimmi population converts (or dies) to Islam in order to avoid excessive taxation and oppressive treatment.
War breaks out among themselves, starvation and sickness kills them off in large numbers. Remnants of the societies they wiped out begin to re emerge and rebuild, starting once again on the path of progress.
Except this time, using our technological advances in science, medicine, and agriculture, we'll keep them alive.