What if they put vetting mechanisms in place but still haven’t figured out what the hell is going on? He should stick to his original plan.
I’ve always thought that much of the “vetting process” was going to set the bar very high — show us your drivers license, and proof of employment for 20 years, and proof of residence in your home country for 20 years, and this, and that, and ...
With the result that no one from Saudi Arabia, Iran, Iraq, Syria, etc would ever be allowed in to the US.
Personally, I would want to offer refuge to persecuted Christians facing genocide. HOWEVER the US must first 100% guarantee that Islamic terrorists do not come through the system. Everything else must be of secondary importance.