What Kas quoted seems reasonable. I think what REALLY happens is that the government does not allow more then two arabs to be checked solely on the grounds of them being Arabs. I'm sure they'd allow more then two to be checked if the Airport crew had a real reason. However, it appears that Ann is blowing this out of proportion, and is singling out arabs as some sort of dangerous terrorist race.
Perhaps a more effective way to stop increased risk of terrorism coming from Arabs is find why they dislike western nations like America so much. I doubt it's because they just hate freedom or something silly like that, it's probably got some sort of grounding in fact, or perhaps a little misinformation mixed in. That'd be more effective then war.
There probably is a faction of terrorists or pro-terrorist people who hate the west because they're christians, probably a faction smaller in number then the number of christians who hate Arabs (I base that on the sheer largness of Christianity and how active it is at trying to convert people) but I think the majority hate westerners for more mortal reasons.