1. Bomb in a Box

Illustration: Brian Staufffer

On 20 March 2007, North Korean dictator Kim Jong‑Il blackmails the world’s wealthiest nations, threatening to detonate a 2-kiloton atomic bomb hidden inside a shipping container somewhere in the port city of Hong Kong unless he receives US $50 billion in gold bullion within 48 hours.

Kim says in a videotaped message addressed to the U.N. Security Council and broadcast by CNN that any attempt to ­disarm the device would result in “a nuclear holocaust for Hong Kong and the crippling of the world trading system.”

The threat sends the city of nearly 7 million into a panic, with many deaths reported as people attempt to flee by any means available.

Experts calculate that a 2‑kiloton bomb detonated on the ground in Hong Kong would kill more people and destroy more property than the 22‑­kiloton airburst that devastated Nagasaki at the end of World War II. That bomb killed an estimated 70 000 civilians and leveled the city center.

The “bomb in a box” scenario is perhaps the worst of all potential terrorist threats. A small a­tomic device detonated at the Kwai Chung port facility in Hong Kong would indeed kill some 87 000 people within hours, says Matthew McKinzie, a scientific consultant to the Natural Resources Defense Council (NRDC) who ran simulations of such an attack for IEEE Spectrum using software designed by the Pentagon.

Because of Hong Kong’s position as a major shipping hub for Asia, such an attack could also paralyze global trade; 90 percent of international cargo now travels in standardized containers.

No one can know whether North Korea’s “Dear Leader,” lording over a half-starved popu­lation and a barren economy, would ever stoop to nuclear blackmail. Yet as the leader of a state, he has a “return address” and therefore ought to be deterred by the certainty of retaliation. Terrorists may not be so easily dissuaded, but they have next to no chance of getting their hands on a ready-made nuclear weapon, says nuclear proliferation expert Thomas Cochran of the New York City–based NRDC.

The threat lies elsewhere, agrees Stephen Flynn of the Council on Foreign Relations, in New York City, one of the world’s experts on transportation security. “A nuclear weapon in a container is a low probability. Why would I stick a postage stamp on it and send it through the system?” What haunts Flynn and other experts is a scenario far easier to pull off: a dirty bomb in a container. On a scale of 1 (no hindrance) to 10 (impossible), “I would rate the ability to sneak a dirty bomb into Hong Kong as a 2,” Flynn says, noting that Hong Kong’s marine terminals handle about 15 million containers per year, which translates into roughly 100 000 containers in the port on any given day. A small dirty bomb could be crafted from about 20 ­kilograms of C-4 plastic explosive, a 500‑gram cobalt “pencil,” such as those used in food irradiation plants, and a cellphone as a trigger. The package would be gift-wrapped in a several-centimeters-thick shield of lead to hide the radiation.

Although the detonation of a dirty bomb in Hong Kong would result in far fewer human casualties—McKinzie’s simulation predicts 61 people receiving a high radiation dose—it would cripple the global container transport system in the blink of an eye, Flynn says. “We simply cannot manage an event like that—the system is too brittle.”

Almost everyone agrees that the protective measures in place today are woefully inadequate. At the end of March, the Government Accountability Office, an investigative arm of the U.S. Congress, concluded that U.S. Customs and Border Protection, which is charged with protecting ports against terrorist attack, was unable to effectively identify “oceangoing cargo containers with the highest risk of containing smuggled weapons of mass destruction,” despite huge investments.

As it happens, Hong Kong could soon become the safest major port in the world. In a pilot project, two of Hong Kong’s largest container terminal operators installed a system that externally scans every incoming container entering two of their loading docks.

The system, which uses machines provided by San Diego–based Science Applications International Corp., does three things at once. A gamma ray imaging device shows the cargo shape and density, a radiation detection device passively checks the vehicle for radio­active material, and an optical character recognition device identifies the container number and links with the cargo manifest data. So even if a weapon were shielded, its dense, bulky profile would still be picked up by the gamma ray imager. The system does not slow down traffic: container trucks pass through the detection equipment at a speed of 16 kilometers per hour. But because it’s only a pilot program, nobody actually checks the scan data, which in a real-world setting would probably take additional time.

Flynn says scanning all containers at every port would change the degree of difficulty for a dirty bomb scenario from a 2 to a 7. Such a system would also allow a suspicious container to be tracked back to its origins, much as surveillance cameras deployed throughout the London Underground enabled investigators to rapidly identify the culprits of the July 2005 bombings.

It is unclear whether the United States and other sea­faring countries will provide the backing for a worldwide system. The Security and Accountability for Every Port Act was overwhelmingly approved by the U.S. House of Representatives in May, but only after an amendment requiring the scanning of all U.S.-bound containers at foreign ports was dropped. Moreover, a $648 million provision, which would have paid for inspectors at 50 foreign ports, additional Coast Guard inspectors, and 60 container-imaging machines, was removed from a national security funding bill moving through Congress in June.

—Marlowe Hood