Air Traffic controllers respond to hijackings on average of 27 times a year. Its not exactly outside there normal operations.
There was no office of homeland security to contact
NORAD has little or nothing to do with civilliain air operations- they look for missiles, not 747's
At the time, NORAD's charge was to protect the nation from intercontinental ballistic missiles, not passenger jets off course.
You have to understand now we know what the objective of the attacks were, at the time of the crisis we did not.
There's also a very real legal dilemma regarding the use of military force, which could cause delays in times of crisis:
It is illegal for the US military to be used against its own citizens or be deployed for action on the soil of the US, unless in times of declared war.
The planes were full of citizens..... sad but true. The military's hands were tied before they could even react
Im pretty sure you could not assemble congress, pass a measure, and deploy in the time from when the threat was first apparent to before the first plane hit.
It is not illegal for national guard trrops however.
Except the national guard doesnt exactly run NORAD does it.
Once the threat was made apparent, SIOP was initiated, (Single Integretion Operations Plan) The first step of SIOP is to secure the chain of command.
This is why Bush spent the day riding around in air force one. The second step of SIOP is to prepare for a massive 'Alpha attack'
This is why all air traffic was immediately grounded, to free up the airspace for military aircraft and to give the ability to track a target without interference from other airborne aircraft. The 3rd step of SIOP is establish air superiority over the us...
Which is why fighters provided CAP (combat air patrol) over major east coast cities and the atlantic coast in the hours following the attacks.
However SIOP was designed to be used in place of nuclear attack, not a terrorist threat using conventional weapons, and was soon abandoned once it was clear the immediate threat had passed.
It wasnt the best plan for the situation, but it was the only one in place at the time, and something is better than nothing.