It surely would be cheaper to arm and train a certain percentage of teachers and staff in each school to carry concealed so that attackers would not know which personnel needed to be shot first. They could induct them all into the army, perhaps, to maintain the no civilian carrying of guns principle.
So France won’t protect their borders, then they’ll have to protect their schools.
I can see the same thing happening in America. But just like at airports, everyone will be treated as a potential terrorist. This is what is taking place by design.
Treat the cause, not the symptom. Why not deport the terrorists?