There is only one issue that will matter in the (very) long term. Parts of the country will end up with uncontrollable knife crime and gang warfare, courtesy of our Afro-Caribbean friends - there is no solution to this, policing or social, it's just the way things are going to be. Other parts of our (temporarily our, but I despair of what "our" means any longer) will become Islamic hotspots. It will happen that limited areas (at first) will implement a sharia law, and you may expect to see road signs outside Wolverhampton such as "You are now entering a Sharia Area - please ensure all women are veiled"
Muslims don't immigrate and integrate, they settle and then demand changes of the host nation - AND GET THEM. This is the huge risk to the Western world.
Chamberlain and his little scrap of paper......