Cheap and Dirty Bombs

During North Korea’s July 2013 "Victory Day" parade, spectators were treated to a curious sight: a truckload of soldiers, each strapped into a chest pack festooned with the black and yellow radiation symbol. A few months later, the art world preserved the spectacle. British tour operator Simon Cockerell found oil paintings at a Pyongyang tourist shop depicting a North Korean commando team parachuting into enemy territory carrying the enigmatic satchels.

The parade images and oil paintings suggest commando-delivered nuclear-related devices of some sort — an understanding consistent with North Korean defectors, who have suggested that the country might possess "backpack" nuclear devices. The United States developed similar munitions, and rumors persist about Russian suitcase nuclear weapons. Few experts, however, believe that North Korea could make a miniature nuclear charge the size of the packs seen in Pyongyang. Given that North Korea appears to be struggling to manufacture the sort of 1,000-kilogram nuclear weapon small enough for delivery by ballistic missile, with only three nuclear tests, backpack nukes seem out of reach.

Another popular explanation for the ominous backpacks is that they are filled with hazmat suits or Geiger counters and belong to a radiological-chemical reconnaissance unit, which wears these defensive suits in contaminated areas. But given the size of the pack compared with the proposed contents, this explanation also seems unlikely.

The one possibility that has been largely overlooked is that this nuke-themed accessory might have been North Korea’s way of conveying the possibility of its use of radiological dispersal devices, better known as "dirty bombs."

Since the 9/11 attacks, the majority of experts and journalists have analyzed and reported that radiological weapons are mainly a terrorism problem involving the pursuit of nuclear violence on the cheap by groups unlikely to have the means to acquire fissile material or the know-how to fashion it into a usable fission device. Under most circumstances, dirty bombs in the hands of terrorists would not be considered weapons of mass destruction, and far more people likely would be killed by the conventional explosive in the device and the ensuing panic than from the radiation dispersed by the dirty bomb.

But this focus on terrorist interest in dirty bombs obscures a now forgotten history: that states — including those with demonstrated nuclear weapons capabilities — were once interested in these very radiological devices as military weapons.

U.S. interest in radiological weapons can be traced back to the early years of World War II, when scientists explored whether radioactive fission products dispersed over enemy territory could have military applications. The United States researched radiological warfare — then called "RadWar" — for both offensive and defensive purposes before abandoning the idea sometime in the 1950s. (The work on offensive uses appears to have ended because nuclear explosives were a far better investment.) British scientists, too, explored the potential for radioactive weapons in the early 1940s.

Declassified documents outline a number of scenarios in which U.S. military and civilian officials pondered the use of radiological weapons, including a proposal by U.S. Army Gen. Douglas MacArthur, following China’s December 1950 entry into the Korean War, for "sowing a band of radioactive cesium across Manchuria as a kind of ‘cordon sanitaire’ against the Chinese advance." The technical details of the exotic devices dreamed up by U.S. weaponeers during this time still remain largely classified.

Throughout the 1950s, the Soviet Union developed its own radiological weaponry — two radiological warheads for the R-2 missile, named Geran (Geranium) and Generator, which contained a radioactive liquid that would be aerosolized by an explosion, drenching enemy units in radioactive fallout. They tested the warheads from 1953 to 1956, until small nuclear weapons for the R-2 became available. It is unclear if the test program ever used actual radiological materials or merely simulants. In an amusing story, one of the warheads sprung a leak, sending the test personnel for cover. The senior scientist responsible for the test climbed to the top of the rocket, ran his finger through the trickle of brown liquid, and then tasted it. "Guys, let’s get to work," he said. "It tastes like crap, but it’s harmless." The liquid was not radioactive, but intended only to simulate the atomization process. (Nevertheless, the scientist allowed himself an extra shot of vodka at dinner to "neutralize the substance and to allay the terror.") The Soviets lost interest in radiological weapons by the late 1960s.

Interest in radiological weapons, however, continued in other parts of the world. Following Iran’s successful "human wave" attacks in which Iranians accepted massive casualties to overwhelm Iraqi units, Saddam Hussein sought to develop air-delivered radiological dispersal devices that could be used in a fashion similar to that proposed by MacArthur in North Korea. Iraq conducted a number of tests on modified Nasser 28 aircraft-delivered bombs — which contained zirconium that had been irradiated in the Tuwaitha nuclear research reactor outside Baghdad — before eventually abandoning the idea. Ultimately, the U.S. intelligence community concluded that Iraq’s radiological device would not have been a significant military weapon; it was a relatively crude device.

It is not known if Iran has seriously entertained the idea of a radiological weapon. Israel, however, has worried about that possibility, and in January 2012 its civil defense force conducted an exercise code-named "Dark Cloud" that was designed to simulate how to deal with the fallout from a radiological attack. According to press reports, authorities tried to downplay the significance of the exercise, but some senior Israeli defense officials have asserted that the gravest threat from Iran could come in the form of a dirty bomb delivered by a cargo ship.

North Korea might consider radiological devices as part of a national nuclear weapons capability, given its historical focus on commando operations. Joseph Bermudez, in his book North Korean Special Forces, noted that Pyongyang fields "one of the world’s largest bodies of elite, specially trained soldiers." North Korea’s special forces account for approximately 10 percent of the soldiers in the Korean People’s Army.

Given the significant interest that North Korea places on commando operations, arming one unit with dirty bombs would not be any stranger than the Soviet Geran warhead or the Iraqi effort to modify the Nasser 28 bomb. Indeed, North Korea might view radiation contamination of critical infrastructure or deployed military forces as a means to impede U.S. and South Korean military operations. Even attacks against civilians that produced mainly panic would likely wreak havoc behind U.S. and South Korean lines, fouling up logistics and troop movement, not to mention their longer-term social and economic costs. During the Korean War — sometimes called the "Forgotten War" — North Korea made heavy use of special operations forces, including division-level guerrilla units. If the past is any guide, any conflict on the Korean Peninsula will involve the extensive use of special operations forces.

If there is a lost history of state-interest in radiological weapons, there is also a forgotten past of arms control efforts to prohibit radiological warfare. As part of the Strategic Arms Limitation Talks (SALT) in the 1970s, the United States and the Soviet Union negotiated a draft treaty on the prohibition of the development, production, stockpiling, and use of radiological weapons. In a rare act of superpower unity, the United States and the Soviet Union submitted the treaty to the Committee on Disarmament in 1979. Oddly enough, this draft treaty seems to have been all but forgotten by the arms control, disarmament, and nonproliferation community.

The Conference on Disarmament, as it is known today, maintained an ad hoc committee on radiological weapons until 1992. Despite the U.S.-Soviet agreement, the initiative foundered due to disagreements among other conference members over the scope of the draft treaty, definitional issues, and the relatively low priority attached to the subject by most delegations. In particular, the forum could not reach consensus on whether to include attacks on nuclear power plants or other facilities that would release radioactivity — a divisive issue that arose after Israel destroyed Iraq’s Osirak reactor in 1981.

Now might be the time to revisit the history of U.S.-Soviet arms control efforts on radiological weapons. Although the Conference on Disarmament remains deadlocked over a number of issues, there may be a new forum in which to revisit this conversation: the P-5 process. First launched in 2009, this ongoing series of formal consultations among the five nuclear weapons states under the Nuclear Non-Proliferation Treaty (NPT) — the United States, Russia, China, France, and Britain — has focused mainly on nuclear disarmament issues involving verification, transparency, and definitions of nuclear terms.

Some P5 states have expressed interest in adding new topics to the agenda ahead of the 2015 NPT Review Conference. Radiological warfare would be a useful addition. Members are likely to share relatively similar views. Moreover, radiological warfare already may have received some attention in the Chinese-led working group dealing with the development of a common nuclear glossary.

Although a P5 renunciation of radiological weapons would be far from a multilateral treaty, an agreement would still constitute an important step to strengthen the norm against dirty bombs — and help discourage a renewed interest by states in radiological warfare. For now, North Korea’s chest packs remain a mystery. Bermudez told NK News that he believes they are as likely to be "stuffed with paper or rags," intended for disinformation.

While North Korea surely didn’t drive real dirty bombs through Pyongyang, it is worth considering the possibility of state interest in radiological warfare. Engaging China and the other nuclear weapon states on this issue may turn out to be useful if it should happen that those enigmatic packs in Pyongyang are indeed filled with more than rags.