Responding to Nuclear Attacks

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Could terrorists steal or build a nuclear weapon?

It’s an unlikely, nightmarish scenario, but one that’s so dangerous it has to be considered. Experts say that a small group—perhaps as few as four expert scientists, without access to classified information—might be able to build a crude nuclear bomb if they could somehow acquire enough highly enriched uranium or even plutonium. Terrorists might also try stealing “loose nukes” from the more poorly guarded arsenals of such nuclear powers as Russia or Pakistan. Powerful nuclear weapons yielding hundreds or even thousands of kilotons are the most dangerous, but smaller bombs—which could range in yield from one-tenth of a kiloton to several hundred kilotons—would be easier to steal or build. Even a one-kiloton nuclear weapon would produce an explosion equivalent to the detonation of a thousand tons of TNT. (The bombs dropped on Hiroshima and Nagasaki were 13- and 20-kiloton weapons, respectively, and they each killed some 150,000 people.)

These scenarios are so frightening-and so enormously difficult to respond to-that nuclear experts have concluded that the government’s primary focus should be ensuring such attacks never happen, rather than responding to them. This fact sheet focuses on how America might try to manage the consequences of such a seemingly unthinkable atrocity.

Is a terrorist nuclear attack on America likely?

No. Making a bomb is not easy, and the necessary components—including plutonium and uranium—are hard to buy or steal. (It would be far easier for terrorists to make a vastly less dangerous “dirty bomb”—a conventional explosive laced with radioactive material—than a nuclear explosive.) Similarly, strategic nuclear weapons—the largest city-killing weapons in nuclear arsenals—are hard to steal and may be difficult to detonate. Somewhat more plausible scenarios, experts say, revolve around terrorists trying to get smaller, battlefield nuclear weapons such as atomic artillery shells, which are harder to keep track of and easier to use. The U.S. government has tried to decrease the risk of nuclear terrorism by working with Russia to secure any “loose nukes,” securing some supplies of plutonium and highly enriched uranium, stepping up intelligence programs, and focusing on such potential nuclear proliferators as Iran and North Korea.

Does al-Qaeda pose a new type of nuclear threat?

Experts say it does. An al-Qaeda nuclear attack would be less damaging than the old Cold War scenarios of nuclear war, but it is also more likely. After the 1962 Cuban missile crisis, the superpowers set up mechanisms to decrease the risk of a global nuclear war, and both the United States and the Soviet Union were deterred by the knowledge that a nuclear strike on its adversary would mean its own destruction. But al-Qaeda, which has expressed a clear interest in nuclear technologies, is not a state, and cannot be thus deterred. The bin Laden network would not be able to unleash a global apocalypse, but it might destroy an American city.

What would be the overall result of a nuclear explosion in an American city?

Devastation. The number of casualties—including basically equal numbers of dead and wounded—would be enormous, and the long-term health, economic, psychological, political, and social consequences would be shattering. The scope of the destruction would depend on a number of factors, including the bomb’s yield, the location of the blast, the nearby population density, and prevailing weather conditions.

How much damage would a small, crude nuclear weapon cause?

According to one estimate, the blast from a one-kiloton nuclear weapon—such as a crude improvised weapon or a stolen battlefield weapon—in midtown Manhattan during the day would:

• Kill more than 200,000 people and injure at least 200,000 more
• Produce radioactive fallout that could kill half the exposed population as far as three miles away within a few weeks
• Demolish most buildings and other structures over eleven city blocks
• Seriously disrupt Manhattan’s transportation, communications, utilities, and other infrastructure.

How much damage would a large nuclear weapon cause?

Again, it’s extremely unlikely that terrorists would be able to acquire a strategic nuclear weapon or get past the safeguards that are in place to prevent its unauthorized detonation. But under the scenario described above, the detonation in Manhattan of a 150-kiloton nuclear weapon would be even more devastating. It is estimated that it would:

• Kill more than 800,000 people and injure 900,000 more
• Produce radioactive fallout that could kill half the exposed population as far as ten to fifteen miles away
• Demolish all buildings and structures within a mile of the blast site
• Set fires that would spread and burn out of control for days
• Knock out many of the city’s major bridges and tunnels, as well as the power grid, communications networks, and other crucial utilities such as water and gas
• Destroy all but one of Manhattan’s major hospitals.