And with Islam running rampant in Europe now, not really caring is about as dangerous as it gets.
The only force which ever threw the Muslims back is Christian fanaticism. If a bunch of religious nutjobs hadn't gathered together to fight them, Europe would have been Muslim centuries ago, and it would have remained as dark and backward as all Muslim countries are today.
Again, we must be careful when dealing with monsters that we do not become monsters ourselves.
What good would it do to win in battle and lose ones soul, just like the person who gains the whole world but loses their soul. Jesus Christ warned us of this...
In addressing the last part about atheists losing Western civilization, I cannot make such an absolutist statement, as I am not an Absolute Being. Perhaps you are? Do you know with absolute, infinite certainty, that they would have lost Western Civilization?