Christianity was all encompassing in Europe until the last 200-300 years. The move away from the faith has been more pronounced in Catholic countries. The 16th and 17th centuries saw protestant , particularly calvinist, countries followed various confessions (westminster, heidelberg, begic etc) in and out of government. The biggest break, unfortunately, occurred in the United States with our Godless Constitution. Followed by France with their godless French Revolution (France arguably fell away permanently at the St. Batholomew’s Day Massacre) From there fell the rest of Europe which culminated in the godless World Wars and modern secularism which recognizes no God and has no concept of the danger of Islam.
I've noticed this myself. Not, IMO, so much that they move farther away, but rather that the move is so fast when it occurs.
Not very long ago at all Spain, Ireland, Portugal, Italy and Quebec were all strongly religious and Catholic.
They are all now among the most post-Christian countries on earth. This seems to have happened much faster than equivalent movement in Protestant countries like Sweden, England, etc.
To be fair, the movement started for the most part earlier in Protestant countries.