Phobia: Irrational fear, dead, or worry. feeling of anxiety without justification

If there is a large and growing group of people who have demonstrated their past present and future ability and will to kill as many people who aren't like them in your area, any fear you might have of that group would be well founded, rational, and healthy.

I don't "fear" Islam or muslims so much as I know what they are currently doing around the world and why. It is a murderous cult and anybody with half a brain should be concerned.