Matt Yglesias on the possibility of retaliatory attacks from al-Qaeda in the aftermath of Osama bin Laden's death:
To me, the main thing we’ve learned about terrorism since 9/11 is that almost nobody living in the United States of America or any country from which you can travel to the USA without a visa (Canada, Western Europe, etc) actually wants to mount a terrorist attack. We’ve done a lot of homeland security since 9/11, but it’s obviously imperfect. You never see a terrorist detonate a bomb in an airport security line, you don’t see terrorists shooting up shopping malls, rogue drivers don’t plow their cars into crowds of pedestrians, etc. There are clearly lots of people eager to fight the United States in Afghanistan and other places, but those people either don’t want to come here or else they can’t. The idea that there’s some sleeper cell waiting for the right moment to strike was very plausible in September 2001, less so in October 2001, even less so in October 2002, and less and less and less and less plausible with every passing year.
Roger that. I think it's worth pointing out that strengthened security measures are probably partly responsible for this, since they make it a lot harder to pull off attacks of any significance. If you want to set off a bomb in an airplane, you either need to hide it in a toner cartridge or in your underwear or whatnot, and that's just inherently unreliable. Even car bombs are harder to make than you think, since the precursor elements are carefully tracked.
Still, the point stands. Obviously terrorists are always trying to think of new ways of creating havoc, and we have to respond to that. Broadly speaking, though, we have responded, and that response has been pretty effective. The United States doesn't have a lot of homegrown suicide bombers, and it's really, really hard for Afghan/Yemeni/Somali/etc. suicide bombers to get over here and do anything spectacular. We're almost certain to be attacked again, but it's equally certain that attacks will be infrequent and far less damaging than 9/11. We shouldn't orient our entire worldview around increased security, and we shouldn't scare ourselves into spending vast amounts of money on it.
At least, that's true for now. In the future, who knows? There might come a time when biological weapons become easy enough to make that our security calculus needs to change. But not right now.