What is enough?

What would have been enough to stop Umar Farouk Abdulmutallab?

His father’s word of his radicalization was not enough to place him on the no-fly list nor was it enough to have his visa withdrawn.

If his visa had been withdrawn, would that had stopped him from getting on the flight on Christmas Day?  Some witnesses claim that he boarded the flight without a passport.  The cancelled visa might have stopped him from actually entering the US but he had no intention of getting off of the plane so the visa wouldn’t have affected him.

Did his ticket have his real name?  If he boarded without a passport, he could have been using a fake name which means that the no-fly list wouldn’t have worked either.

Is the only solution to bring the troops home and lock down the borders?

Related:  No easy answers. (via Small Dead Animals)