If they don't, they will be turned into laughingstocks. This might give France a terrorism problem if radical Islam leads to terror, but I don't think it will turn France into a Muslim nation. It will turn France into a country that's mostly Atheist but has a group that everyone likes to laugh at, and within that group, a few sociopaths that can be made scapegoats by various politicians for all of the country's ills.
You need to read the Islam book the Koran. Then write those statements. For it seems if they don't have the power yet in their land in which they live. If their children leave their religion they try to get them captured. In order to send them back to the home land. Where either they bury them to their waste or behead them. It is not a very pleasant scene. By the way Islams are getting more power by the day. England has a mayor that is Islam in Manchester. So what you think can't happen will most likely happen if God allows it.
Isn't that the way all forms of prejudice work? Make whatever small population is the target into a growing "threat" that needs to be dealt with before it can come and destroy our way of life?
The thread in question sounds like Islamophobia to me. Most Muslims who emegrate to these countries come not as a part of some massive Islamic group think conspiracy to take over via making more babies than our European friends. I mean they don't all think the same way, we're talking about individuals here not The Borg hive mind.\
To be sure there are issues that we definately need to confront in the Muslim world and theology regarding persecution of religious minorities, the rights of women and seperation of church and state (which I suppourt in any country including my own U.S.A.) However, I'm deeply concerned that in taking every opportunity to stigmatize, and ostrasize these people while holding up the classic prejudiced excuse of self-preservation we'll succeed in creating very fertile ground for terrorist recruiters.
And before anyone asks yes I do own a Qu'ran which I've read, it was a gift from a classmate of mine. He gave me a sparkly new Qu'ran which he paid for, and I gave him a Gideon's Bible which I got for free. I like to joke to myself that it's a pretty good parallel to how our two faiths view salvation, but that's off the point.