One other thing...
These are mostly 20 something and younger single males coming in from African etc. nations, MEast as well as S.America......An interesting thought ...if you wanted to go into these nations for resources but the violent conflicts just go on and on year after year , what better way to stop the conflicts without shedding blood then to stop the young from being recruited to those forces by leaving a door of escape wide open..... If they can’t fill the ranks of those dying they soon enough will have no armed forces to fight their conflicts.....if there’s no conflicts then that’s a straight shot to the resources.
Permit me to add something to your comments. When it comes to most immigrants (from Italy to the US, for example), the children are more willing to assimilate than their parents.
But that is not true when it comes to islamists! The younger ones are usually more radical than the older ones. This is a serious problem, and one that governments are choosing to ignore, at their great peril.