North Korea’s Nuclear Explosion: Less Than Meets the Eye

Was Pyongyang’s presumed nuclear test truly as advertised? The author, whose background includes two stints making intelligence assessments of Pyongyang’s capabilities and intentions, presents his take on the recent underground test and what it will mean for U. S. interests in East Asia. Additionally, he suggests what it will all mean for the countries of the region more directly affected. —Ed.

by David T. Jones

The North Korean nuclear test is a “fizzle”—technically if not in politico-military and diplomatic terms.

Although experts continue to work on the exact parameters, its low calculated seismic signature (approximately 4.1 on the Richter scale) and trivial estimated explosive power (as low as 200 tons of TNT) indicate that it was a failed nuclear test. A nuclear explosion, indeed, but nonetheless a failure.

Constructing a nuclear weapon is now sixty-year-old technology with its basic techniques extensively known, indeed widely published for over twenty years. Given the required amount of fissionable material, a decent chemist, electrical engineer, and machinist could combine to make a basic nuclear weapon. If a country is totally determined to create nuclear weapons, it is a question of time and expense rather than an adventure into the unknown to do so. A wide variety of countries have successfully built nuclear weapons, whether admitting it (United States, UK, France, China, Russia, India, and Pakistan) or not (Israel). And others (Iran today) and (Iraq before 1991) headed down that track. Nevertheless, although no longer “rocket science” in requiring cutting edge technological complexity, it is not a trivial engineering project.

The North Koreans are engaged in two programs to produce fissionable material. The first and more mature of their programs is to extract plutonium from fuel rods in a nuclear reactor. To play “nuclear weapons for dummies,” several isotopes of plutonium (Pu) are produced while a nuclear fuel rod is in a reactor (mainly Pu 239 and some Pu 240). The Pu 239 is the nuclear material which, when violently compressed to great density, will generate a nuclear explosion. Pu 240 will also go critical. but at a much earlier point before a maximum yield can be reached. Thus the quantity of Pu 240 that can be present before it causes a fizzle is limited to just a few percent. There are other ways a nuclear test can fail, such as failure of the outer shell of conventional timed explosives designed to produce the ideally spherical implosion or even, conceivably, a badly machined plutonium metal sphere. Experts who know plutonium weapons design can probably identify a dozen additional errors that would yield a fizzle rather than a Nagasaki level explosion.

Although the North Koreans are also engaged in an alternative nuclear program to “enrich” uranium to weapons grade levels, it is more likely that the test was of a plutonium-based nuclear weapon.

There were two alternative explanations beyond the “fizzle,” each highly unlikely but which require passing note, if only to dismiss them. Conceivably, Pyongyang could have so mastered nuclear technology and sophisticated computer simulation that, without any intermediate steps, it has moved into extreme miniaturization — and 200 tons of TNT would be a miniature nuclear weapon well beyond U. S. capabilities for an extended period after our first nuclear test. Others in the blogsphere have hypothesized that the NK nuclear weapon was designed to be an anti-aircraft missile warhead to counter fleets of attacking U.S. war planes or even the “igniter” for a thermonuclear (hydrogen) bomb.

Historically, however, the first successful nuclear test has been in the vicinity of a device generating about 20,000 tons of TNT, the size of the first “Trinity” U.S. test in 1945, which used plutonium; the smallest initial test to date was the Pakistani test at approximately 9,000 tons of TNT. From that point, a state nuclear program struggles to “weaponize” the nuclear device by reducing its physical dimensions to a size that can be delivered by a plane or missile. Consequently, a mini-nuke appears to be well beyond current North Korean science/engineering ability; it would be the equivalent of launching a manned moon mission without previously building a long-range ballistic missile.

The second possibility was that the explosion was not nuclear at all, not even a failed nuclear blast. Rather (in theory) it could have been a fuel-air explosive which, when detonated underground in terrain whose geology is essentially unknown, combined with an underground chamber designed to distort the seismic signature unique to a nuclear explosion, could generate sufficient ambiguity so that all those observing from a distance — often of thousands of miles — cannot be sure what they have observed. Again, this scenario failed the “Occam’s razor” rule, i.e., the least complex explanation is the most probable. And the identification of radioactive particles released by the test certifies that it was a nuclear test. Indeed, Pyongyang’s nuclear program has been underway for upwards of twenty years (by some accounts since the 1960s). At some point, it was going to choose to make a political statement.

Under the “fizzle” scenario, however, one should hypothesize that there will be another test, or tests, in the sooner rather than later time frame. Senior NK leaders have threatened/promised such. And then there has been back-and-forth media statements regarding whether or not Pyongyang plans another test. Nevertheless, if the North is focused on nuclear weapons for national security and/or international blackmail, it must to be confident that it can build them — and a fizzle doesn’t demonstrate anything beyond engineering incompetence. So those who are willing to accept pseudo-promises that there will be no further NK tests may also want to invest in tropical resorts in Pyongyang.

Need for a Valium
That said, the United States is fueling the frenzy with statements about the unacceptability of North Korean nuclear weapons, statements that imply pre-emptive action despite President Bush’s statement that no military action is intended. Other states, including Canada, have tossed hype in the hysteria direction by blaming the United States for the NK program. And Secretary Rice’s recent Far East trip may have been politically and diplomatically necessary to calm jangled ROK and Japanese nerves, but is unlikely to have changed any of the regional realities. In this instance, at least, we should step back and do the diplomatic/intellectual equivalent of taking a Valium.

Frankly, the U. S. government has no responsibility for either stimulating or stopping the North Korean nuclear program. Underway for at least two decades, Pyongyang has temporized, evaded, and just plain lied about its objectives. It appreciates the squeamish and largely inconsequential nature of the international UN consensus—what does Zambia or Bolivia care about happenings on the Korean peninsula? Pyongyang has played the oh-so-concerned interlocutors with the adroit ruthlessness of Sudan’s Darfur deniers or Iran’s ayatollahs. Being condemned by the UN and its latest silly sanctions is akin to being gummed by a toothless sheep; if one doubts UN irrelevancy, ask Israeli diplomats.

As an interlocutor, North Korea’s leader Kim Jong-il is, to be minimalist in a characterization, not reliable. There has been no agreement that the North has honored; the savagery with which the regime exercises political control over its population has been recounted past fruitful repetition. Dealing with the North Koreans is akin to giving the neighborhood pedophile an opportunity to baby-sit your little girl. The demand that Washington negotiate one-on-one with Pyongyang has been a fifty-year objective designed to split the United States from South Korea and de-legitimize the ROK. We have rejected this ploy for over half a century; it remains the correct approach. Indeed, there is no absence of opportunity for North Korean to convey its positions to American diplomats — either directly at the United Nations or through numerous third parties.

Reality in Northeast Asia
There are four powers in the region with a greater stake in limiting North Korean nuclear ambitions than do we: China: Russia, Japan, and the Republic of Korea are there by geography. We are there by choice — and we could choose to depart. Many of North Korea’s neighbors want to make its nuclear status our problem; it is not our problem — and we need constantly to push the problem back to Seoul, Tokyo, Beijing, and Moscow. If they do not want a nuclear Pyongyang, they need to bribe or bludgeon the North; that is, pay any financial/economic/diplomatic price to assure that the program is eliminated, or alternatively, take military action to prevent it from happening.

My bet is that they will do neither. China and Russia do not fear NK nukes and have no qualms about Pyongyang leveraging Seoul and Tokyo. Watching Kim disconcert Tokyo and Seoul is the equivalent of a light comedy soap opera for Beijing and Moscow. They know the North is not suicidal enough to attack them and they have no interest in a regime change in Pyongyang that would either require expensive intervention/rebuilding or stimulate floods of refugees across the Yalu River. They can keep the North Korean pit bull on a leash of their choosing, while ignoring its growls that so roil South Koreans and Japanese.

For their part, the ROK and Japan fear more the economic risks of war than the political perils of a nuclear North Korea. And, if they won’t confront Pyongyang, why should the U. S. government do it for them? Over the decades of tension, Pyongyang has assassinated ROK leaders, built tunnels under the demilitarized zone, kidnapped Japanese citizens to serve as language instructors, and fired rockets over Japanese territory. The ROK and Japan have responded with the equivalent of that diplomatic cudgel: “a stiff note of protest.”

If one cannot deter, one must endure. And now we will deny Pyongyang the right to import luxury goods. Oh the agony!

After all, North Korea is not doing anything illegal — it has officially withdrawn from the NPT, and states have the right to create the weapons that they desire. Rather than direct and immediate military action, the ROK and Japan will temporize. Along with deploying the best possible ballistic missile defense, they will begin to debate creating nuclear weapons programs of their own (while denying that they have any interest, intention, or desire to do so). Regardless of bilateral treaty commitments with Seoul and Tokyo, in their view, Washington cannot be counted upon to remain on guard for them forever, and the only real ripostes to Pyongyang’s nuclear weapons are comparable weapons of their own.

And the United States, after these programs are (much to our professed surprise) completed, will withdraw military forces from the region. We have manned the ramparts in Northeast Asia for over sixty years. It is time for a changing of the guard. Or rather it is time for those who we have guarded for so long to assume their guardian responsibilities.