Lets take a look at mass shootings here in the u.s.
https://www.washingtonpost.com/news/...the-deadliest/
See, ii wondered this morning...just how many of these islamic extremist mass shootings have we had? How many in total? If we sealed our borders, how many of these shootings could have been prevented? In order of.priority, taking on the worst cause first, what should be our first target to change?
Now, barring muslim immigrstion might be the easiest solution....but we would still not have solved the problem, considering the above.