I'll draw this picture on a smaller scale.
Anyone every heard of Gary, Indiana? Ever heard of the musical "The Music Man"? Famous song/show. Well let me tell you "the rest of the story".
Back in the 50's, Gary built up quickly. Lots of working families moved their, many immigrants from Europe. Built small starter homes, worked the steel mills and oil refineries. And as they built some wealth, these families moved on to nicer homes in adjacent towns. Home values dropped as more homes were on the market, and many poorer blacks/hispanics wanting to get away from Chicago moved in. This isn't a racism statement, but the new residence simply had no work ethic and were happy to pop out babies & collect welfare. Keep in mind, this was going into the 60's when civil rights and Black Panthers were growing in influence. And, remember the mob & crime that Chicago is famous for (Al Capone for example). Also don't forget how drugs became commonplace in the 60's/70's.
So in the 70's people started avoiding driving through Gary at night. Gary was renamed (unofficially) "Plywood City", as windows everywhere were being replaced with sheets of plywood from all the vandalism. In the 80's, nobody drove through Gary at night and you locked your car doors as you drove through in daytime. And the 90's were even worse, you didn't drive through Gary during day or night, period. Crime was rampant, drug use was everywhere. Schools were simply pre-prison daycare.
Why do I tell this story? It's the same thing here. When the first, second, or 100th welfare recipient moved into Gary, nobody saw the implosion of the city. Same with Europe, when the first wave of muslims arrived over the past decades, nobody saw it as a strategic takeover (I'm talking recent times, not the pre-Crusades invasion). I see islam as a plague. It is based on lies. It's foundation is perversion and pure evil. And as things stand, I believe Europe is lost (barring some massive pushback, Crusade-like event).
Will the US learn from them? Will the plague take over the whole world? Heck, look at the whole Bosnian/Kosovo wars. Other than trying to distract from Monica Lewinski, those wars 100% helped muslims and hurt historic Europe/Christians.
Just read the history of the Ottoman Empire (which ended with WW1).