I just finished writing a column about our insane post-9/11 security apparatus, so I can hardly believe I'm about to say what I'm about to say. But here's Matt Yglesias on airport security:
One question I always have when I go through airport security is exactly how many planes the relevant authorities think al-Qaeda would be blowing up if planes were no better secured than an intercity bus. My experience of intercity bus travel is that there’s absolutely nothing stopping a person from bringing a bomb onto a bus. And yet, over the past ten years exactly zero buses have been exploded by terrorists. A person with the means and inclination to blow up an airplane, who finds himself stymied by tight airline security, could just go blow up a bus instead. But nobody does this. So my baseline assumption is that approximately zero airplane detonations have been prevented by airline security screening, since were screening preventing suicide bombers from blowing up planes we’d see bomb-displacement onto other transportation segments.
Matt goes on to admit that "terrorists do seem to have a unique fascination with planes," but that only increases his estimate to one saved plane.
And hell, I can't prove him wrong. But seriously? Given everything we know about terrorist attempts to bring down airplanes — the 1995 Bojinka plot, 9/11 itself, Richard Reid, the British plot to blow up 10 airplanes using liquid explosives, the underwear bomber, the cargo plane plot — do we really think terrorists wouldn't have blown up a helluva lot of planes if doing so didn't require a ton of planning and secrecy, but instead was as easy as packing a couple of kilos of C4 into your carry-on luggage and strolling on board? Common sense suggests that most bombing plots never get very far precisely because they have to be carefully planned to evade airport security, something that makes it hard to pack enough punch to do any serious damage. But if getting on a plane were really as easy as boarding a bus, the evidence of the past decade warns us that airplanes would be dropping out of the sky with alarming frequency.
It's worth asking whether the fantastic amount of additional post-9/11 airline security has made air travel much safer. That's a lot harder to say. But Cuban hijackers ended the era of boarding planes like buses. We've all been standing in line at airport security checkpoints since the 70s, and even the pre-9/11 security routine was enough to prevent most airline bombings. Given al-Qaeda's obvious fascination with air travel, it's hard to imagine that any of us would feel especially safe boarding a plane if there were no security at all.