Bin Laden and his followers are using the paranoia of the western world meet their ends.
Think about this a bit:
If the pawn with the explosives in his pants had blown that plane out of the sky over Canada what would have been the result?
There would have been speculation that it may have been a terrorist bomb. There would have been an intense effort to recover debris and piece it together, inquiries and commissions would follow and after months or years it would be determined that it was probably a bomb. Instead the thing did not detonate so the knowledge and result was an immediate spiking of fear, shutting down or delaying air travel at the peak of the busiest season.
Remember that another dupe already used this tactic with the explosives in his shoe. That would not detonate either but it had every traveler removing shoes at airport security. I wonder if all did not go according to plan...................