The Scariest Terror Threat of All

By Bruce Schneier
Wired News
June 15, 2006

For a while now, I have been writing about our penchant for "movie-plot threats" -- terrorist fears based on very specific attack scenarios.

Terrorists with crop-dusters, terrorists exploding baby carriages in subways, terrorists filling school buses with explosives -- these are all movie-plot threats. They're good for scaring people, but it's just silly to build national security policy around them.

But if we're going to worry about unlikely attacks, why can't they be exciting and innovative ones? If Americans are going to be scared, shouldn't they be scared of things that are really scary? "Blowing up the Super Bowl" is a movie plot, to be sure, but it's not a very good movie. I decided to raise the stakes.

So I announced a Movie-Plot Threat Contest on my blog:

Entrants are invited to submit the most unlikely, yet still plausible, terrorist attack scenarios they can come up with. Your goal: Cause terror. Make the American people notice. Inflict lasting damage on the U.S. economy. Change the political landscape, or the culture. The more grandiose the goal, the better. Assume an attacker profile on the order of 9/11: 20 to 30 unskilled people, and about $500,000 with which to buy skills, equipment, etc.

The contest spread across the internet. Even The New York Times wrote about it. By the end of the month, the blog post had 782 comments. I printed them all out and spiral-bound them so I could read them more easily. The cover read: "The Big Book of Terrorist Plots." I tried not to wave it around too much in airports.

The submissions fell into several broad categories. The first was attacks against our infrastructure: the food supply, the water supply, the power infrastructure, the telephone system. The idea is to cripple the country by targeting one of the basic systems that make it work.

The second category was of big-ticket plots. Either they have very public targets -- blowing up the Super Bowl, the Oscars -- or they have high-tech components: nuclear waste, anthrax, chlorine gas, a full oil tanker. And they are often complex and hard to pull off. This is the 9/11 idea -- a single huge event that affects the entire nation.

The third category was low-tech attacks that go on and on. Several people imagined a version of the D.C.-sniper scenario, but with multiple teams. The teams would slowly move around the country, perhaps each team starting up after the previous one was captured or killed. Other people suggested a variant of this with small bombs in random public locations around the country.

A fourth category had actual movie plots, often comical or unrealistic, some with science-fiction premises. That wasn't what I was looking for, so I mostly ignored them.

The best ideas tap directly into public fears. In my book, Beyond Fear, I discuss five different tendencies people have with evaluating risks:

  • People exaggerate spectacular but rare risks and downplay common risks.
  • People have trouble estimating risks for anything not exactly like their normal situation.
  • Personified risks are perceived to be greater than anonymous risks.
  • People underestimate risks they willingly take and overestimate risks in situations they can't control.
  • People overestimate risks that are being talked about and remain an object of public scrutiny.

The best plots leverage one or more of those tendencies. Big-ticket attacks leverage the first. Infrastructure and low-tech attacks leverage the fourth. And every attack tries to leverage the fifth, especially those attacks that go on and on.

I almost don't want to pick a winner, because the real point is the enormous list of them all. And because it's hard to choose. But after careful deliberation, I chose the winning entry by Tom Grant. Read it; it's chilling. Although planes filled with explosives is already a cliché, destroying the Grand Coulee Dam is inspired. The chain reaction destroys most of the other dams on the Columbia River, taking out the West Coast power grid for months.

Congratulations, Tom.

If you think Tom's entry is scary, consider that I received a bunch of e-mails from people with ideas they thought too terrifying to post publicly. Some of them wouldn't even tell them to me. I also received e-mails from people accusing me of helping the terrorists by giving them ideas.

Both of these reactions make the same erroneous assumption: that terrorist attacks are easy, and all terrorists need are a few good ideas. But if there's one thing this contest demonstrates, it's that good terrorist ideas are a dime a dozen. Anyone can figure out how to cause terror. The hard part is execution.

Some of the submitted plots require minimal skill and equipment. "Twenty guys with cars and guns" -- that sort of thing. Reading through them, you have to wonder why there have been no terrorist attacks in the United States since 9/11. I don't buy the "flypaper theory" that the terrorists are all in Iraq instead of in the United States; it just doesn't make any sense. And I don't buy that our post-9/11 security programs have made it impossible for terrorists to operate within the United States -- although I do believe that our successes in intelligence and investigation have made it harder.

But mostly, I think terrorist attacks are much harder than most of us think. It's harder to find willing recruits than we think. It's harder to coordinate plans. It's harder to execute those plans. It's easy to make mistakes. Terrorism has always been rare, and for all we've heard about 9/11 changing the world, it's still rare.

earlier essay: Make Vendors Liable for Bugs
later essay: It's the Economy, Stupid
categories: Terrorism
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Photo of Bruce Schneier by Per Ervland.

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