Even with the most stringent vetting one can never be sure when any muslim will suddenly start following the example and teachings of their prophet.
Sudden jihad syndrome can strike at any time with no warning.
You are so right on that.
When a person "gets religion" , not that uncommon an occurrence in many religions, they get back to basics.
If a Christian "gets religion" they are not a threat to you and will actually pray for your salvation.
If a Muslim gets religion they will do what Allah and Muhammad want done and kill you if you resist conversion or the spreading of Islam. - Tom