There would seem to me multiple components involved in intercession, starting with bag searches and metal detectors in proximity to potential targets. However, we have been asking law enforcement to produce a response to _anticipated_ crimes. To do that, we need to do some new things:
1. Acknowledge that a limited “opposition” — “Islamists”, not Islam — believes that it is at war with us, including most Muslims, and that it is — in this order — talking, walking, planning, operationalizing, and acting.
2. Broaden — by reducing strictures on — detention periods and surveillance of persons of interest, so that the talker and walker who pings the FBI radar, as has happened many times now, may enjoy some surreptitious follow-up as needed (say as when acquiring new weapons from the local gun shop).
3. In the region of freedom of speech, we need law recognizing “jihadi-talk” as involving conspiracy and incitement, and then we need permit to act against those who mix the poison that gets in through the ears and eyes and those who deliver that poison by publishing it. There have long been traditional limits to freedom of speech — conspiracy, incitement, libel, and slander. In the area of conspiracy and incitement, we have expected direct contact or cooperation between parties, but today we well know that mediated contact perhaps bolstered by related presentations in the mosque are sufficient to contribute to the motivation of an attack.
4. In the region of freedom of religion, we have to recognize that a religion that has in several aspects the motivation of subduing the world by force in fact represents an alien and invasive political program. As regards those aspects, challenge, confrontation, and reformation involve time, short or long, and the kind of time required is long as regards determining what options are forward and then very short, i.e., the time it takes a person to make a small decision in a good direction.
On those “options forward”, there are today many channels, some congruent with leaving scripture alone but interpreting it more deeply — or tortuously depending on one’s perspective; some unabashedly reformist and determined to eliminate “Political Islam” — and then rejection of the the faith through the abandonment of religion altogether, conversions to other faiths or traditions, and any number of adjustments as seem fit to those who flatly reject extremist programs.