The local news here is full of ruined Christmas stories. Besides the usual Christmas Eve house fires, stolen presents, and drunken family fights, the stories were heavy on airline travel delays. Most blamed the weather for ruining their Christmas travel. Others see a more sinister hand at work. This was on the Drudge Report today:
Difficulties this weekend at US Airways and other airlines may be a harbinger of things to come... Developing...
A nearby link on the same page (in the trough) points a finger at flight attendants and other workers calling in sick.
Here is a more unpleasant scenario. It is not a theory of the recent holiday travel problems, but an extrapolation of their effect.
If the desired result of a terror attack is damage to the US economy, and the result can be attained by disrupting air traffic, then numerous false terrorist threats at key airports, properly timed, could create a gridlock. It is not difficult to imagine that the initial disruption would provide targets of opportunity for terr cells to carry out small but real assaults on the airport system. Perhaps crude technical assaults on power lines or communications hardware serving airports would be enough. If an aircraft could be seized or destroyed by terrorists early in the gridlock, the crisis could be perpetuated with renewed false threats.
This type of disruption would be costly commensurate with its duration. Secondary effects must also be considered. Some Americans are already complaining about the inconvenience and invasiveness of airport security measures. Nobody likes to think about such possibilities, but I believe we need to be considering anything and everything.
I haven't a good suggestion for countering these types of disruptions, except to offer the example of the people of London during the Blitz. Patience and a stiff upper lip could prevent disruption from becoming chaos.