No, it will take more than "a couple of decades".
https://en.wikipedia.org/wiki/Islam_in_Europe (Macedonia doesn't count, because it's the Albanian minority there that is merely culturally Muslim, unlike the bellicose Syrians etc. in Germany). However, gradually Muslims will become a dominant minority in Western Europe: they will introduce sharia zones, where white harlots cannot walk around semi-naked without a significant risk of getting raped, and if she gets raped, the courts will (as they already do) habitually acquit the perpetrator(s) and so on.