Uncontainable: North Korea’s Loose Nukes

If you’re worried that U.S. diplomacy with Pyongyang is heading nowhere, and you think attacking North Korea is unimaginable, the Bush administration has good news: President George W. Bush, in private comments reported May 5 in The New York Times, has indicated that the United States may shift its North Korea strategy away from both a military strike and from diplomacy and instead focus on containing Pyongyang’s plutonium exports through means short of military attack. More emphatically, Secretary of State Colin Powell, responding to Tim Russert May 4 on NBC’s “Meet the Press,” declared that the United States would “absolutely not” allow North Korea to export plutonium, the key constituent of a nuclear bomb. Americans, it appears, can sleep easier.

Except they can’t. The administration’s new tack might appear soothing at first glance, but closer examination reveals it to be deeply disturbing. Indeed, President Bush should know what his scientific advisers have certainly deduced: Short of a diplomatic solution or a provocative and risky military action, it will be impossible to stop Pyongyang from exporting plutonium.

Given the destructive potential of even a single nuclear bomb—500,000 people dead in a midday New York City explosion is not an unreasonable estimate—an effective plutonium blockade must be airtight. A drug-interdiction scheme that stopped 90 percent of all drug shipments would be considered overwhelmingly successful; but a scheme that stopped 90 percent of North Korean plutonium transports would be an abject failure if the remaining 10 percent included enough plutonium for even a single nuclear bomb.

Unfortunately, plutonium is extremely difficult to detect. It emits little radioactivity—one could stand next to a weapon’s worth of plutonium for weeks without becoming sick. Finding a grapefruit-sized ball of plutonium—about the amount needed for a basic nuclear weapon—requires that a detector be held within roughly 25 meters. Detection, then, cannot be done by satellite or even by reconnaissance aircraft operating off the Korean coast.

Indeed, according to a little-noticed report in late April in London’s Daily Telegraph, the Pentagon is proposing up-close inspections of North Korean exports that would, in theory, ensure that all traffic leaving North Korea is plutonium- and missile-free while stopping short of a complete economic blockade. Administration officials see this selective blockade as a natural extension of last winter’s joint Spanish-American police action in which a North Korean missile shipment was seized en route to Yemen. (The ultimate release of that shipment has no doubt left a bitter taste in the mouths of many administration officials, who would surely relish the opportunity to redress the weak image projected by the release.)

Unfortunately, such inspections are unlikely to work well enough. Consider what would be required to completely stop North Korean plutonium exports. Controlling land borders would be challenging but perhaps not impossible. At the tightly monitored South Korean border, radiation detectors could be set up at checkpoints for a moderate price. Controlling the Chinese border would be far more difficult. Illicit smuggling takes place regularly across the 780-mile border, meaning detectors could not be restricted to official checkpoints. Though the Chinese could conceivably halt and inspect every truck crossing the border, intercepting individuals would be much more difficult and could cost millions of dollars. In fact, rather than trying to search every individual, the Chinese would be better off installing upward of 10,000 radiation detectors. And 10,000 detectors is an optimistic estimate—it assumes the North Koreans would attempt plutonium shipments in weapon-sized batches. If Pyongyang divided its plutonium into chunks 10 times smaller, three times as many detectors would be required. (Indeed, the detectors would be so tightly spaced that the physical barrier to would-be smugglers might prove as much a defense as the sophisticated radiation detection.) And, technical barriers notwithstanding, the political obstacles—in particular, securing China’s active cooperation—would be high, since Beijing thus far has been unwilling to take actions that would completely alienate Pyongyang.

Blocking sea-based smuggling would be less technically challenging but far more politically provocative. In contrast with the extreme difficulty of locating and inspecting every individual crossing the North Korea-China land border, identifying and searching every ship leaving North Korean waters would be relatively straightforward. Still, no technology would allow inspectors to certify North Korean ships as plutonium-free without first stopping, boarding, and carefully inspecting those vessels.

All of which leads to a major problem with the Bush administration’s ostensible plan: It could easily provoke North Korean military action. A sea-based containment regime would be tantamount to a naval blockade, an action that North Korea has repeatedly stated would be treated as an act of war. The same problem would hold for air traffic. Though packages arriving in friendly countries could be scanned for plutonium, many shipments might be sent directly to hostile or uncooperative states such as Iran or Syria, where intrusive radiation scanning would be impossible. After all, North Korea is already known as one of the world’s leading proliferators. It has allegedly sold ballistic-missile technology and other weapons, often shipping them by air, to unstable regimes such as Pakistan. By contrast, bundling a nuclear weapon’s worth of plutonium with such a shipment would be trivial, and the United States would be effectively powerless to stop it. Indeed, the only way to prevent air shipments without North Korea’s cooperation would be to shoot down every aircraft, military or civilian, leaving North Korean airspace. If boarding North Korean ships would be risky, imposing a flight moratorium by military force would be insane.

To be certain, some short-term stopgaps against plutonium exports would be prudent. The United States might accelerate installation of neutron detectors at our ports of entry, giving us a better chance to prevent plutonium leaked from North Korea from being delivered to a U.S. city. It should also make clear to Pyongyang that, if a bomb constructed from North Korean plutonium is detonated on U.S. soil, forensic experts may be able to identify its origin—allowing America to retaliate accordingly. The mere possibility that the United States could retaliate against an attack involving North Korean plutonium might be enough to deter Pyongyang from exporting it in the first place. These steps are no substitute for a comprehensive solution, but they would at least reduce our vulnerability without risking war.

One need not agree with North Korea’s official news agency, the KCNA, which recently remarked that U.S. policy “can not be construed otherwise than ridiculous jargons of political imbeciles [sic],” to question the wisdom behind the administration’s apparent move. By imposing a selective blockade, the administration seems to be attempting to walk a fine line, seeking to avoid the concessions necessary for a diplomatic solution, the risks involved in a military attack, and the dangers of doing nothing. But it is chasing a dangerous fantasy. Indeed, an intrusive inspections regime runs military risks nearly as great as those of an attack on North Korea’s plutonium plants while avoiding the benefits—near certainty that North Korea will be unable to export plutonium. And, unlike a potential diplomatic solution, a blockade will not deter eventual trade in highly enriched uranium, the other half of North Korea’s nuclear program, since enriched uranium gives off less radiation than plutonium and thus is even harder for inspectors to detect. Indeed, according to a container-security study published last year by Stanford’s Center for International Security and Cooperation, it would be nearly impossible for the United States to detect enriched-uranium imports into America.

Sadly, while the administration’s approach appears new, it is conceptually familiar. When President Bush took office, he inherited precarious but promising negotiations over North Korean missiles initiated by the Clinton administration. Against the advice of many, Bush quickly abandoned the diplomatic track, falling back on the promise of a technologically immature missile defense. Today, the administration seems again to be preemptively preparing the nation for a diplomatic failure by brandishing the dubious promise of a cure-all defense. And, once again, that defense is an illusion.