Over the last few days, the UK raised its terror threat level to “severe,” prompting a number of changes in their approach to air-traffic security.  The Mirror reports on one potential explanation for this concern — a sudden increase in attempts by people on the “no-fly” list to board planes destined for the US:

Two men were stopped boarding US-bound planes at Heathrow days before Britain’s terror threat was raised to “severe”.

News of the incidents came hours after Home Secretary Alan Johnson lifted the threat level amid fears that al-Qaeda is planning an attack. …

Security sources say an Egyptian was stopped last Saturday as he tried to board an American Airlines flight to Miami. A man from Saudi Arabia was banned from boarding a United Airlines flight to Chicago the next day and sent back to Saudi. …

Anti-terror officials said the past week had seen an “unusually high” number of people on their no-fly list trying to board US-bound planes.

The British have a number of reasons to move the threat level up.  Hamid Karzai will pay a visit to the UK, as will Hillary Clinton and UN Secretary-General Ban-ki Moon, to discuss the security issues in Yemen and the NATO mission in Afghanistan.  Without a doubt, an attack on this conference would be quite a coup for terrorist groups, and the UK is well aware of the risks.

But still, the threat they’re seeing is not so much aimed at the UK as it is at the US.  Even after the failure of Umar Farouk Abdulmutallab, which could have just been a training issue, al-Qaeda seems intent on exploiting security holes in air travel to the US.  For the moment, we’re catching people using the “no-fly” list, although it’s not clear whether these people were actual threats or even the same people as whose names appeared on them.  It does show that we need to keep up with the lists and err on the side of caution, at least under the current security processes we have.

At some point, though, the no-fly list is not going to stop an attack.  AQ will either get lucky or get smart with a terrorist whose identity was previously unknown, and that terrorist may have a lot more skill at detonating underwear than the erstwhile EunuchBomber.  We need to rethink airport security from A to Z to implement a system that catches terrorists while keeping the system running for everyone else.  Israel uses such a program, which will be more expensive to implement but a lot more efficient at catching terrorists than backscatter imaging and 20% patdowns on random passengers, neither of which would have stopped Abdulmutallab.