How should the World confront the threat of Islamist terror ?

It would have been wonderful if they had screened people carefully before allowing them in the country. I have friends who are Moslem but they are very moderate and have never heard anything threatening from them. They are all warm and hospitable people. A couple that we are friends with would invite us to dinner etc. I saw a large painting of Jesus in their little prayer area and that surprised me because typically Moslems don’t have pictures of people on their walls. The wife was born of a Jewish family and converted. Which made that even more interesting. They have moved back to Iran but sometimes come back for visit. The man is wealthy and has a successful business. They moved back after their children all got educated and the youngest was capable of living on his own.