Parallslism falls apart on one basic fact.
Hitler and the Nazis had a real shot at conquering the world militarily. And came remarkably close to accomplishing it. (Though their victory would have been short-lived once America got The Bomb.)
There is absolutely, positively NO WAY Islamists are going to conquer the world militarily.
Weak kneed Europeans and Americans might roll over without a fight, and conversion/immigration could conceivably bring them to power, but they have no hope whatsoever of conquering the world against genuine opposition. Very different from the Germans.
Surely you don’t expect to see a perfect parallel to historic events- the main point here is that Islam is a threat. It doesn’t have to be a *military* threat to be dangerous.