It's a good thing that the radical Islamists have tipped their hand early. If they were smart, they would wait until they had sufficient strength to accomplish their take over.
They were trying to do it piece-meal. They wanted to establish muslim ghettos that could be incubators for what you propose. If future immigrants from the muslim world were not settling in these ghettos, they could be better assimilated into western culture. This would diminish the aility to contol and brainwashg the muslim immigrants into jihad. The goal is to create no-go enclaves of radical islam that will be the seeds of jihad.