But, how likely is a 100% attack. Try sending a bunch of folks on the east coast to a meeting. There will ALWAYS be delays, cancellations and unavoidable problems. There weren't just 4 Saudi crews, there were 6 or 8. They all left from home that morning and reported to an airport. Somewhere, there was a wreck on the tollway and some didn't get there. Those were the Saudis that we should have tracked down!
Most of the Saudi terrorists, however, in the country today, came across the much easier Mexican border. They will launch the next attacks.