France did not, it only allows one culture ie the french (secular) one and it passes laws to enforce it. eg it bans words like: email, blog, supermodel, take-away, chewing gum, parking, weekend, low-cost airline, hash tag... all to protect the French culture.
france wrote the book on how to do secularism badly. it's very different from the american (and sensible) idea of secularism: the state stays neutral. in france they ram secularism down your throat in a way that would make the Saudi's proud. freedom of thought, conscience and religion? sorry, not in the libre republic.
I say this as an atheist and secularist. run from the way the french do it.