They just failed to take into account for a lot of new factors... More over, the entire French Military doctrine was too stiff to quickly respond to the german invasion.

These were the points of my metaphor. Build big installations & rules & people stop thinking. that's huan behaviour. That's why Israeli airport security procedures don't advocate racial profiling.

Tell people to focus on one group & they won't pay attention to anybody else, and you only need one anyone else - and they don't need to actually be terrorists, they just need to be mules.