North Korea's Big Bang

Did Pyongyang just take a big step toward an arsenal of nuclear-tipped missiles?

When the email notification of a shallow 4.9 tremor near the North Korean nuclear test site landed in my inbox, courtesy of the United States Geological Survey, I went to Twitter:

It go boom.

The magnitude of the explosion, now revised to 5.1, is significantly larger than North Korea's previous nuclear tests in 2006 (4.3) and 2009 (4.7). Seismic scales are logarithmic, so 5.1 is much larger. The corresponding size of the explosion or "yield" is several kilotons, or thousands of tons of TNT -- although we should treat all yield estimates at this point as rough approximations. (I've posted a long discussion on the perils of estimating yield based on the simple seismic data at ArmsControlWonk.com.)

The point is, this one is bigger. Although it's not nearly so big as the modern thermonuclear weapons in the U.S. arsenal -- which range from hundreds of kilotons to a megaton -- you really wouldn't want this dropped in your neighborhood.

More importantly, however, North Korea has announced that the device was a "miniaturized and lighter nuclear device with greater explosive force than previously." What this boils down to is a North Korean claim that this nuclear weapon will fit on a missile like the Nodong. Or maybe even the KN-08, which the North Koreans say over and over is intended for us. Like a valentine.

The question is, do we believe them? And if we do believe them, does it mean we have to think about this problem differently?

There are basically two approaches to these questions, which arise from differing interpretations of the rather small yields of the first two North Korean nuclear tests -- a few hundred tons in 2006 and about two kilotons in 2009.

One view is to insist the North Koreans prove they are not terrible at building nuclear weapons. Here, I need to introduce you to a term of art: "simple fission device." This is a bulky nuclear weapon of the sort that the United States dropped on Nagasaki. That bomb weighed 4,000 kilograms (over four tons!) and contained six kilograms (about 13 pounds) of plutonium. The yield was about 20 kilotons. It was affectionately called "The Gadget," which is funny in precisely the opposite way that it's amusing to name a Chihuahua "Bruiser." The massive Gadget would have been far too large to be delivered by a missile, if the United States had any at the time. No country has ever built a simple fission device and discovered it did not work. Hence, "simple," as in anyone can do it.

Until the North Koreans, that is. In this telling, the North Korean nuclear program, like the North Korean missile program, required multiple tries to achieve success: in this case, building a Gadget-sized simple fission device. The third time was a charm -- but North Korea is still stuck with 1945 technology, wondering whether the damn thing will fit in the bomb bay.

The second view, to which I am inclined, is that we ought to take the North Koreans at their word. This view arises from the judgment that North Korea's disappointing yields in 2006 and 2009 are not the result of technical incompetence so much as outsized ambition. The North Koreans tried to skip some steps and go directly to miniaturized devices.

The United States quickly reduced the mass and dimensions of its nuclear weapons, largely by making the process of implosion more efficient. When I visited the historical collection at the Atomic Weapons Establishment in Aldermaston, England, I was surprised to see a rather explicit description of the use of air pockets among the lenses to improve the efficiency of explosions. There are other tricks, too, like suspending or "levitating" the plutonium pit. (The physicist Ted Taylor elegantly illustrated the idea by asking, "When you hammer a nail, what do you do? Do you put the hammer on the nail and push?") The result was a steady reduction in size, without the loss of explosive power. One of the first miniaturized U.S. fission weapons, the Mark 7, weighed just 750 kilograms and used considerably less plutonium than the Gadget.

It's no coincidence that the U.S. intelligence community, in the late 1990s, estimated that 650-750 kilograms was probably the best that North Korea could do without testing. The Mark 7 is used as a proxy for what a new nuclear state might attempt to build. China gave Pakistan a roughly comparable design, which Pakistan may have further shrunk, as well as sold to Libya and god knows who else. There are reports that Iran had access to a still more compact Soviet design.

The general view, however, is that miniaturized weapons are unreliable without testing. The question is whether the North Koreans attempted immediately to build a Mark 7-sized device, perhaps because they placed too much confidence in data acquired from the Soviet Union or Pakistan, or because they were just plain drunk on juche.

There is some evidence for this view, although it is admittedly circumstantial. In 2003, David Sanger reported that the United States noticed the North Koreans doing an unusual amount of testing with high explosives. The typical path toward shrinking nuclear weapons involves reducing the amount of explosives needed to compress a sphere of either plutonium or highly enriched uranium. The intelligence community, according to Sanger, concluded that North Korea was attempting to do better than a simple fission device, trying "to make nuclear warheads small enough to fit atop the country's growing arsenal of missiles."

Then, in 2005, a certain North Korean official defected. "Kim Il-do" claimed to have worked for the Second Economic Committee of the National Defense Commission, which oversees North Korea's nuclear and missile programs. Kim had some interesting things to say about North Korea's nuclear weapons program. Here is a translation from the Korean article by my colleague, Hanah Rhee:

Mr. Kim, during an interview with [South Korea's] National Intelligence Service, said that North Korea had manufactured a one-ton nuclear warhead with four kg of plutonium. He also said "North Korean scientists reported to Kim Jong-il that the weapon is functional, however, they have doubts about the level of performance that they manufactured." Mr. Kim said, "North Korea is not confident whether their large-sized nuclear weapons can actually work in practice which is why they are developing a smaller 500 kg version." 

At the time, I was inclined to doubt the guy. That's not how the United States, or anyone else, did it. And for good reason -- if North Korea were to test such a weapon, the result would probably be a humiliating failure.

Then North Korea tested a humiliating failure.

North Korea told China to expect a four-kiloton yield. That's broadly consistent with what one might expect from a device with only four kilograms of plutonium. The actual result was a few hundred tons' worth of yield. Not something you'd want dropped on your neighborhood, to be sure, but also not something you'd be eager to explain to the Dear Leader. Suddenly, at least to me, Kim Il-do didn't seem so crazy.

If you believe this second theory of North Korea's strategic development, then North Korea isn't incompetently following the U.S. or Soviet nuclear weapons development path. With fewer tests, North Korea is trying to move more quickly to larger, deliverable warheads based on the experience of others. Although I suspect I'm in the minority, I still believe that the North Koreans' ultimate goal is a stockpile of missile-delivered thermonuclear weapons. Broadly speaking, I suspect this test is a step toward that end. There are many technical details that we don't know at the moment -- and may never know. We don't know yet whether the device used plutonium, highly enriched uranium, or both, and we might never know. We also don't know how North Korea made a bigger bang this time -- whether the progressively larger explosions represent improvements in the existing approach or changes in the entire design philosophy.

But we should treat North Korea's own statements about miniaturization seriously.

Not taking the North Koreans seriously compromises our ability to formulate a realistic approach to managing the problem. We have a tendency to see North Korea's nuclear program as a vaguely ridiculous enterprise that exists largely to extort the United States. This view underestimates North Korea's ambition with regard to its nuclear weapons program and the importance that the leadership in Pyongyang places on it. Kim Jong Un is not going to take the route Muammar Qaddafi did and give up his nuclear and missile programs -- they are much too central to his regime's ideology. (This is to say nothing of the terrible precedent that Qaddafi's overthrow set. After learning about the last few minutes of his life, I sat gingerly for a week.)

If you want to know how the North Koreans think about their nuclear weapons, watch these subtitled clips from the North Korean propaganda film, The Country I Saw. The complete, verifiable, and irreversible disarmament of North Korea, as it were, will require a comprehensive settlement of the questions arising from the Korean War. Let's not hold our breath.

Being realistic about the dim prospects for disarmament should include an appreciation that things can get worse. A lot of pundits and politicos treat nuclear weapons as an either/or proposition. You have ‘em, or you don't. A classic example of this sort thinking was a comment by Colin Powell, who argued in 2002 that the collapse of the 1994 Agreed Framework, which had frozen North Korea's nuclear program, was harmless because the North already had nuclear weapons. "What are they going to do with another two or three nuclear weapons?" he asked on one of the Sunday talk shows. (He seems to have done five that day, giving variations on theme of "so what?") A small stockpile of reliable warheads small enough to ride a missile is clearly worse than a single one-ton device that doesn't work. And, if we do nothing, whatever stockpile North Korea has in 10 years' time could easily be worse than its current arsenal.

We ought to be careful about encouraging the North Koreans to prove it to us. I understand, and support, the Obama administration's insistence on the talking point that we do not accept North Korea as having the formal status of a nuclear state. But making it clear that Pyongyang's isolation cannot end with a nuclear-armed North Korea does not require insisting that it demonstrate each measure of capability. In the mid-1960s, the Chinese made some interesting choices about how to ensure the neighbors took them seriously. One was to mount a miniaturized nuclear weapon on a DF-2 missile and fire it 1,200 km across China. That was the fourth Chinese nuclear test. (The design from that test, which used highly enriched uranium, was the one that later showed up in Pakistan and Libya. One presumes more copies are floating around.) The North Koreans seem unwilling to test in the atmosphere for a variety of reasons, so I suspect this is an unlikely precedent. But it is worth keeping in mind that things could be much, much worse. There is value to simply managing a problem, especially when there are no better options.

We can all recite a list of options to manage this particular headache. Prominent among them: partial agreements to freeze fissile-material production, nuclear testing, and rocket launches. These steps will not eliminate North Korea's capabilities, but now it's my turn: So what? What better plan can you imagine? I think back to former diplomat Bob Gallucci's frustration with critics of the much-maligned 1994 freeze, admittedly an unsatisfying approach:

"When I came back with the Agreed Framework deal and tried to sell it," he said, "[Many people] hated the idea of trying to solve this problem with a negotiation.

"And I said, ‘What's your -- pardon me -- your fucking plan, then, if you don't like this?'

‘We don't like --'

"I said, ‘Don't tell me what you don't like! Tell me how you're going to stop the North Korean nuclear program.'

‘But we wouldn't do it this way --'

‘Stop! What are you going to do?'

"I could never get a goddamn answer."

That's because there isn't a goddamn answer. There is no better plan that stops the North Korean nuclear program. The North Koreans will probably cheat and we will be rewarding bad behavior. So f'ing what? Unless, of course, you have a better idea. Then, by all means, be my guest.

Chung Sung-Jun/Getty Images

National Security

Friends with Benefits

No, Mr. President, it's not OK if our allies get nuclear weapons.

Barry O. is going to talk about nuclear weapons again. Someone sober up the Nobel Peace Prize committee.

Speaking at the Munich Security Conference -- think of it as Davos for people who love armored formations -- Vice President Joe Biden indicated that the president would use the forthcoming State of the Union address to advance "a comprehensive nuclear agenda to strengthen the nonproliferation regime, reduce global stockpiles, and secure nuclear materials."

The trope of Joe Biden indulging in all manner of low-class pleasures is now firmly established thanks to the tireless efforts of the Onion. I couldn't read that passage of his speech without imagining Biden riling up the crowd before some especially awful hair metal band takes the stage: ARE YOU READY FOR SOME BARACK OBAMA? I CAN'T HEAR YOU!

Obama will say all the right things, of course. He'll probably declare victory on his campaign promise to secure all vulnerable fissile material during his first term. He may call on the Senate to ratify the Comprehensive Nuclear Test Ban Treaty. If he's feeling it, he may threaten to take negotiations on a treaty banning the production of fissile material out of the deadlocked Conference on Disarmament. Finally, he might also say a few words about the administration's increasingly poorly named 90-day Nuclear Posture Review Implementation Study, which the administration started in the summer of 2011.

As the president surveys the landscape of all things nuclear, it would be nice -- well, I would appreciate it, at any rate -- if he said a few words about what may turn out to be the most consequential decision he makes in his second term: How he plans to respond to nuclear programs in North Korea and Iran.

Oh, he'll say something, of course. Obama will surely express the normal platitudes about not "accepting" nuclear weapons in either country, offering an outstretched hand if they would only unclench their fists, yada, yada, yada. But there is one subject that no one in his administration is willing to touch, unless they stumble into it sideways before apologizing and moving on. The interesting question isn't how to stop North Korea or Iran, but how we manage the inevitable pressures from our friends and partners to seek their own nuclear weapons capabilities in response.

One of the oldest problems in the book on nuclear weapons is the so-called "Nth country" problem -- the simple idea that each new nuclear state inspires or terrifies yet more to join the club. It's worth taking a moment to reflect on U.S. nonproliferation policy and how we've dealt with this problem throughout the nuclear age.

One of the simplest questions I get asked when I give talks to a general audience is this: Why is it OK for the United States to have nuclear weapons, but not Iran or North Korea? It's a good question and the answer matters a great deal.

The initial U.S. position on the spread of nuclear weapons was basically, "It's good when our friends do it, but bad when our enemies try." The early history of U.S. approaches was a mixture of efforts to preserve a nuclear monopoly and, when that failed, proliferate selectively to our friends. The United States helped the United Kingdom build nuclear weapons, it stationed its own nuclear weapons overseas as an advertisement for the wonders of nuclear deterrence, and it pushed NATO towards accepting something called the Multilateral Force whereby U.S. nuclear weapons would be stationed on NATO ships with multinational crews. If you've ever seen Cédric Klapisch's L'auberge Espagnole, it would be like that -- but with nuclear weapons. The Italians even outfitted a cruiser with launch tubes.

The real problem in the early nuclear age was encouraging states to get into this ghastly business in the first place. One of the clearest statements of this line of thinking was offered by a Harvard professor named Henry Kissinger: "One of the chief tasks of United States policy in NATO, therefore, is to overcome the trauma which attaches to the use of nuclear weapons and to decentralize the possession of nuclear weapons as rapidly as possible." And you thought Ken Waltz was the only person who thought like that!

Eventually, the idea of selective proliferation gave way to a slightly more reasonable approach. As China neared its first nuclear detonation in the early 1960s, the U.S. foreign policy elite went into a minor panic. (Quivering hands must have dropped countless cucumber sandwiches on Mr. Pratt's parquet.) All the usual approaches were considered -- but they seemed especially ridiculous when transplanted to Asia. Actual policy proposal: Help India build a nuclear weapon to counter China! Eventually, as in the case of most knotty problems, a commission was formed. Lyndon Johnson asked Roswell Gilpatric, a former deputy secretary of defense and shall we say "man about town," to look at the problem.

Unlike most commissions, this one produced something useful. (I'll give you a minute to recover.) The Gilpatric Report figured out what I take to be the central fact of the nuclear age: that nuclear weapons pose a shared danger to all countries -- this, only two decades into the nuclear age. Narrowly speaking, the commission observed, if both the United States and Soviet Union encouraged their friends to acquire nuclear weapons, pretty soon everyone would have them. That would be unwelcome. So, despite our deep ideological differences, the superpowers had an incentive to cooperate. The Gilpatric Report laid out a sensible set of nonproliferation measures that the United States might pursue with the Soviet Union, including treaties against proliferation, nuclear testing, and the production of fissile material. Fifty years later, we're still working on Roswell Gilpatric's list of recommendations.

I don't want to oversell how dramatic the shift in U.S. policy was after the Gilpatric Report. This isn't a Hollywood movie. Henry Kissinger didn't slap his forehead and say "Oh, vat an ass I've been," although that certainly would have been appropriate. The Nixon administration, for example, agreed to seek ratification of the Nuclear Nonproliferation Treaty (NPT) -- but only on the condition that we never, ever ask any of our friends to sign it, least of all the West Germans. Privately, the Nixon administration accepted Israel as a sub rosa member of the nuclear club and initiated a robust program of nuclear cooperation with France that might have seemed at odds with our newfound interest in nonproliferation, if it hadn't been kept secret for a couple of decades.

The NPT has plenty of flaws. It was, among other things, about 20 years too late -- but better late than never. By 1970, five states already had tested a nuclear weapon. The treaty recognized this reality, striking one of many bargains: no more nuclear weapons states, with those already in the club agreeing to good-faith efforts toward disarmament. The deal isn't fair -- life, you may have noticed, is like that -- but it was the only deal possible and better than none at all. People who talk about an NPT 2.0 are either fools or on staff at the Physics Research Center in Tehran. This is the best deal we're getting; we need to make it work.

Despite a cottage industry of claiming the NPT is doomed, the treaty has done rather well in several respects. Over time, nonproliferation became the norm for U.S. policy. We did eventually encourage and, when necessary, strong-arm our friends into signing the treaty, halting nuclear weapons programs in places like Australia, Sweden, South Korea, and Taiwan.

We've gotten to the point today where there does seem to be something untoward about building nuclear weapons, with proliferation at the moment largely occurring among states that are relatively isolated within the international community. Advocates of the NPT like to mention John F. Kennedy's remark that, without action, 15 or 20 or 25 states might acquire nuclear weapons by 1970. The number gets the headlines, but it's worth looking at the intelligence estimate his comment was based upon. The 15 or 20 or 25 states included all the states that could build nuclear weapons. Noticeably absent are many of today's problem children. Where the NPT succeeded was in limiting proliferation to the hard cases -- whether we call them pariahs, rogues, or states of concern. That is no mean feat. When military dictatorships in Argentina and Brazil ended, so did their nuclear weapons programs. When South Africa gave up apartheid, it also gave up the bomb.

At the same time, the norm against proliferation is something we must work to maintain. That cottage industry I derided -- and of which I am part -- is necessary. Left to their own devices, most diplomats, regionalists, and politicians would fatally compromise the nonproliferation regime with ever more exceptions and excuses. The United States has never made nonproliferation its top priority. At best, it's one of many interests -- and often the losing one. The Soviets invaded Afghanistan in 1979, so the Reagan and George H.W. Bush administrations looked the other way while Pakistan built nuclear weapons with Chinese assistance. There is a special place in nonproliferation hell for the George W. Bush administration, which hijacked the nonproliferation agenda as an excuse to invade Iraq and then, in some misguided geopoliticking, sought a waiver (or blew a gaping hole) for India in the Nuclear Suppliers Group, making India the only country in the world eligible for nuclear imports without the obligations that would come with joining the NPT. Mr. Obama, despite his lofty nonproliferation rhetoric, has been as willing as any other president to bend the rules for his friends.

Which brings us back to his State of the Union address. After declaring all that "vulnerable" fissile material secure and reminiscing about the good old days in Prague, Mr. Obama will have to say something about North Korea and Iran. He'll take a swipe or two -- more in sadness than anger -- at their intransigence. But what he really ought to do, and what would be hard, is to talk about how he'll respond when our friends want to start down the same road.

North Korea is about to test a nuclear weapon for the third time. The usual types in South Korea and Japan have made all manner of irresponsible statements. Negotiations with Iran are going nowhere. Whether or not you believe that Iran's program is paused, as I do, Tehran's neighbors are also sounding worried. Our friends aren't going to ask for the bomb directly, at least not at first, but they've already started asking if, perchance, we might not bend the rules a little here or there. Maybe, they ask, we could agree to let them develop longer-range ballistic missiles, or would we mind if France sold them really great cruise missiles? Or borrow the plutonium out of the reactor fuel we sold them? Or spin a few centrifuges?

Not for nuclear weapons, of course! Oh, no, no, no. Did you mention hedging? I didn't mention shrubbery. Topiary is an interesting hobby, don't you think?

There is every temptation to respond to these hard cases by making more exceptions. They are our friends. None of them has had active nuclear weapons programs for at least 20 years. (You did what in 2000? Never mind, we're good.) Historically, the United States helped build the norm against proliferation by making it clear to some of our friends that the choice was between nuclear weapons and an alliance with the United States. Today, Seoul or Riyadh might reasonably conclude that the formula works in reverse: Would Washington abandon an ally over an act of proliferation? What are a few nuclear weapons among friends, anyway? What if they keep it on the DL?

At some point, the exceptions will destroy the rule. Having five nuclear weapons states was a necessary compromise, but a compromise all the same. The holdouts of the 1970s were toughies. Israel already had built nuclear weapons by 1970, but just not tested them -- isn't that better than overtly joining the club? India tested in 1974 when the treaty was still young, claiming its nuclear test was a "peaceful nuclear explosion." Pakistan couldn't sign because India wouldn't. After India tested again in 1998, we simply had to "deal with the realities" of India's de facto nuclear weapons possession in seeking special treatment for New Delhi at the Nuclear Suppliers Group. And so on, and so on.

Every single one these exceptions made perfect sense at the time. And that's the problem: so will all of the exceptions that Barack Obama's national security teams asks him to make in the next four years. Do we put nuclear weapons back into South Korea? Consent to their reprocessing of American-made spent nuclear fuel? Sell the Jordanians, Saudis, or Emiratis who knows what? Each of these decisions will represent a perfectly sensible opportunity to strengthen relations with a key partner at only a small cost to the broader nonproliferation regime as a whole. We'll tell ourselves that the harm we do pales in comparison to harm already done by North Korea or Iran. This will be true, but will be beside the point. The aggregate wisdom of the foreign policy community, over time, will doom the regime as a whole.

I don't think the administration sees it this way, which worries me. A certain administration official derided some of the people critical of their nonproliferation policies -- okay, me -- as nonproliferation "purists" because we believe that the rules ought to be applied in a consistent and impartial manner to our friends, as well as our enemies. Worrying about special pleading, however, doesn't make one a "purist." It makes one aware that the legitimacy of any international regime is a fragile thing. It makes one careful not to let too many small changes accumulate catastrophically. The diplomat's preference to treat every case as sui generis amounts to having no rule at all, save that of the jungle. Yet if there is one realization of the nuclear age, it is the law of the jungle is simply too dangerous in a nuclear-armed world. That is the logic behind Kennedy's fear of 25 nuclear-armed states. And behind Gilpatric's conclusion that "the spread of nuclear weapons poses an increasingly grave threat to the United States." And it was, I thought, the logic behind why Barack Obama stated his "commitment to seek the peace and security of a world without nuclear weapons."

We must have rules, even for our friends. We have enough exceptions already.

Library of Congress/Records of the Office of the Secretary of Defense