Dirty Bomb, Muddy Thinking

If I were Iran, if I were Iran — a crazed fanatic, I’d say let’s get a little fissile material to Hezbollah, have them carry it to Chicago or some other place, and then if anything goes wrong, or America starts acting up, we’ll just say, "Guess what? Unless you stand down, why, we’re going to let off a dirty bomb." I mean this is where we have — where America could be held up and blackmailed by Iran, by the mullahs, by crazy people. So we really don’t have any option but to keep Iran from having a nuclear weapon.

–Mitt Romney, May 17, 2012

Governor Mitt Romney’s description, caught on video, of what he considered the real nuclear threat from Iran has further undermined his national security credentials, showing a fundamental misunderstanding of nuclear threats. Iran’s nuclear program has nothing to do with dirty bombs. Terrorists would not use uranium — from Iran or anywhere else — in a dirty bomb. It is unclear if Gov. Romney was just riffing, or if his advisors had fed him this line of attack. But it is dead wrong.

Nuclear bombs are serious business, and preventing their spread and their use against the United States is perhaps the paramount duty of the president, who, of course, is also responsible for any decision to use America’s own arsenal. The main reason we are so concerned about Iran is that its uranium-enrichment facilities could produce the fissile material needed to make a nuclear bomb. Anyone running for the highest office in the land simply must know the basics about dirty bombs, nuclear weapons, and the threat from Iran. This video does not help Gov. Romney prove that he does.

A dirty bomb is basically a truck bomb laced with radioactive materials. Such a device (also known as a radiological weapon) uses conventional explosives like dynamite or C-4 to spew radioactive materials over large areas. The explosion would be relatively small, but victims would be exposed to life-threatening levels of radiation. The radiation would prevent emergency response teams from reaching the victims quickly and could contaminate large areas for years, requiring expensive cleanup.

A terrorist could also do a reverse dirty bomb: bring explosives to a source of radioactive material such as a nuclear reactor, a spent-fuel pool, or a factory making radioactive isotopes.

Dirty bombs (which have never been used) are very different from nuclear bombs, which trigger a chain reaction in a small core of fissile material — highly-enriched uranium or plutonium — to produce a massive explosion. The explosion produces heat, blast, and radiation that all cause catastrophic damage.

The key here is that dirty bombs do not use fissile material. They do not use enriched uranium or plutonium — the fissile material that Gov. Romney cites. The reason is simple: These materials, perhaps counterintuitively, are not radioactive enough. Their radioactive emissions don’t travel far and are blocked by simple barriers, including skin and clothing. A dirty bomb would use small amounts of highly radioactive materials such as cesium or cobalt, not uranium. Even specks of these elements send out deadly gamma rays that penetrate walls and bodies causing immediate injury.

The Federation of American Scientists has calculated that a mere 41 grams (1.4 ounces) of cesium-137 in a dirty bomb could contaminate most of Manhattan. By contrast, it would take 1,460 tons of low-enriched uranium to get the same levels of radiation. That pretty much tells you all you need to know. Iran does not have any plutonium, so getting "a little fissile material to Hezbollah" would mean shipping them some 1,400 tons of uranium — when all Iran has now is 6 tons total.

Iran’s production of enriched uranium has nothing to do with dirty bombs. The core problem is that Iran is enriching uranium it says is for reactor fuel but could be turned into fuel for nuclear weapons. The most important reason to contain Iran’s nuclear program is to prevent a dangerous, destabilizing nuclear arms race in the Middle East and an emboldened Iranian regime — not to prevent Iran from giving terrorists nuclear materials for a dirty bomb. And it is crucial that anyone involved in the discussion of Iran’s nuclear program — and certainly the Republican presidential nominee — understand this.

That is not to say that dirty bombs are not a serious problem. The closest we have every come to seeing one used was in November 1995, when Chechen rebels placed a cache of cesium in a trash can in a Moscow park as a warning of what they could do. Neither the Chechens nor the original source of the cesium was ever identified. Experts worry that it is just a matter of time before some group actual set off a dirty bomb.

The problem is that there are hundreds of sources of highly radioactive materials. They are found in minute quantities in doctors’ offices, mining operations, and smoke detectors. They have literally scores of civilian uses. Terrorists could steal the ounces of material required for a bomb from one of the manufactures of these civilian devices, or simply purchase it through a covert operation. The basic solution is to reduce the usage of radioactive material (most applications have non-radioactive alternatives) and better secure those supplies that remain.

This must be an international effort. The 53 nations that gathered at the second Nuclear Security Summit in Seoul this year took the first steps.* They recognized that "identifying nuclear smugglers, recovering nuclear and radiological material outside of regulatory control, and prosecuting those responsible are important and effective activities to help prevent terrorists from acquiring nuclear or other radioactive materials." The next summit in The Netherlands in 2014 will add control of radiological materials to the list of joint and national actions already under way to secure global stocks of fissile material. Dirty bombs will join their big brother in global control efforts.

So, for the sake of argument, let’s say that Romney was just identifying yet another nuclear-related security threat facing the United States and confused "dirty bomb" with "crude nuclear device." That still leaves his larger point about Iran’s leaders being "crazy people" — which is equally problematic.

If you think Iran’s mullahs are crazy, then there is nothing you can do to stop them from getting a nuclear weapon and using it to destroy Israel or an American city. Not military threats, not sanctions, certainly not negotiations. They are crazy; they don’t respond to reason. Your only real option is to kill them. Charles Krauthammer recently wrote an entire column arguing just this point.

But it is important to note that this is not what America’s military and intelligence leaders believe.

In February, Fareed Zakaria asked Chairman of the Joint Chiefs Martin Dempsey, "When you observe Iranian behavior, does it strike you as highly irrational? Does it strike you as sort of unpredictable, or do they seem to follow their national interests in a fairly calculating way?" Dempsey replied: "I’ve been confronting that question since I commanded Central Command in 2008. And we are of the opinion that the Iranian regime is a rational actor. And it’s for that reason, I think, that we think the current path we’re on is the most prudent path at this point."

Some members of Congress did not like that answer. In a congressional hearing a few weeks later, Dempsey was pressed by Rep. Tom Price, who said he was "stunned" by Dempsey comment and wanted to know if he still stood by his statement. The general did not hesitate:

Yes, I stand by it because the alternative is almost unimaginable. The alternative is that we attribute to them that their actions are so irrational that they have no basis of planning…. Thucydides in the fifth century B.C. said that all strategy is some combination of reaction to fear, honor and interests. And I think all nations act in response to one of those three things, even Iran. The key is to understand how they act and not trivialize their actions by attributing to them some irrationality. I think that’s a very dangerous thing for us to do.

Former Mossad chief, Meir Dagan, agrees: "The regime in Iran is a very rational regime," he told 60 Minutes in March. So does Director of National Intelligence James Clapper, who told the Senate Intelligence Committee in January:

We continue to judge Iran’s nuclear decision-making is guided by a cost-benefit approach, which offers the international community opportunities to influence Tehran. Iranian leaders undoubtedly consider Iran’s security, prestige and influence, as well and international political and security environment, when making decision about its nuclear program.

If Governor Romney disagrees with these intelligence and military assessments, he should explain why, and what he would do differently. But first he needs to spend a bit more time on the basics of nuclear weaponry if he ever hopes to have his finger on the ultimate button.

* Correction: This sentence originally said 54 nations attended the Nuclear Security Summit.