> The simple presence of them might be enough of a deterrent The planning for 9/11 took several years, $500k in financing, and had a lot of moving parts betwee

> The simple presence of them might be enough of a deterrent The planning for 9/11 took several years, $500k in financing, and had a lot of moving parts between recruiting, research, travel/visas, flight training etc. It's hard to believe that people motivated at that level would truly be deterred by what you see happening at the typical American airport these days.