“What happens to Europe if it turns out that its Muslims do not want to integrate?”
Muslims have decided not to integrate. Demographics are the destiny of Europe, just as they are the destiny of the USA. Europeans have already chosen an Islamic future based on the immigration policies of the last half century and the low birth rates of the indigenous population.
The US is heading down a similar path but it is not yet too late for illegal immigration to be stopped and legal immigration to be stopped in order to allow sufficient time for the current immigrant population to assimilate. If current policies of open borders immigration continue, assimilation will not occur and the unique American experiment with limited government will end, supplanted by a socialist dictatorship.
Give us Barabbas.
Not going to happen. Rather the USA will break up into different nations.