Oliver Burkeman had an excellent investigation published in the Guardian's Weekend magazine yesterday.
It examines the reactions to terrorist threats to air travel over the last thirty years, with input from experts.
It draws the conclusion that governments are forever reacting to the last threat to airborne security with physical measures. But they are unable to keep ahead of the terrorists. Governments stop toe-cutters, plastic knives, liquids etc going on board planes but there are many weapons which can still be used. Ones' own hands being obvious ones.
And Gordon Brown has recently announced billions of pounds worth of building work around airports to "increase security". But all the terrorists need to do is to drive a few miles to the next airport which isn't protected in such a way.
This is the security game," (Security expert) Schneier says. "We take away guns, so they use bombs. We take away bombs, they use boxcutters. We take away boxcutters, they hide explosives in their shoes. Take away shoes, they use liquids." Take away liquids, he might have added, and they attack airports, as at Glasgow earlier this year; Brown's plans for barriers and parking exclusion zones follow the rules of the game perfectly.
Instead of spending on infrastructure and measures, to try to keep one step ahead of the terrorists, the article concludes that the answer lies in psychology, and simple studying of passengers before they get on board aircraft:
Which leaves one more option, largely absent from the British approach to security, and fraught with ethical difficulties: if you can't stop people bringing bad things on to aircraft, why not try to identify the bad people instead? Replace technology with psychology, in other words. "The way to prevent aeroplane terrorism is not to keep objects that could fall into the wrong hands off aeroplanes," Schneier says. "A better goal is to keep those with the wrong hands from boarding aeroplanes in the first place."