This is necessary. Most crimes committed in the US are from foreign nationals and again countries with high numbers of religious extremists ends up being religious terrorist and you can′t allow them to come destabilise the US. The recent anti-semitic attacks point to that, just last week, an Egyptian national threw fire on peaceful protesters who are US indigenes who are protesting against the Israeli hostages condition under Hamas, meanwhile Muslims in the US have came out en mass to protest against Isreal and nobody threw fire on them or shoot them. We can′t keep living with people whose worldviews is death and violence. No national allows it and definitely not US.
“Trump reinstates US travel ban, bars citizens of 12 countries - Reuters”