One possible explanation for a failed test is that the North Koreans attempted to skip directly to an operational weapons design (say 1000-2000 lbs like the US Mk 7). Indeed, this was precisely what was reported in the press in 2003 based on changes in the nature of North Korea’s implosion testing at Yongdok—something I blogged about at the time:
So, could North Korea build a Mk 7-like warhead?
According to Chuck Hansen’s Swords of Armageddon, Los Alamos dramatically improved implosion techniques, permitting a six-fold weight reduction from the aptly named Fat Man to the Mk-7 –which Hansen estimates as 1,600 lbs with a 30” diameter.
Expertise in implosion techniques is clearly driving CIA concern about smaller North Korea warheads. David Sanger’s July 2003 article was prompted by the detection of an “advanced nuclear testing site in an area called Youngdoktong” in North Korea. What was special about that testing site? The revelation that “equipment has been set up to test conventional explosives that, when detonated, could compress a plutonium core and set off a compact nuclear explosion.” It stands to reason that the CIA saw the North Koreans working on implosion and inferred that they were trying to reduce the weight of their warhead designs.
So, if (and it is a big if) a couple of shacks at a test site prove that North Korea has become very proficient at implosion, then Pyongyang might be able to manufacture a warhead small enough to fit on a Taepo Dong 2—assuming the untested Taepo Dong 2 performs as advertised.
The warhead, however, would not be very reliable without nuclear testing. I doubt the North Koreans can run the table, building an ICBM and miniaturized warhead without testing either. At the very least, Pyongyang has to worry that doubts like mine will be widespread, severely undermining whatever existential deterrence Pyongyang enjoys.
Wow, I guess I was right. I had no idea.
There may be a parable here about authoritarian societies and proliferation. Kim Jong Il probably believed the weapon would work because, as a colleague suggested, “doubts about a system don’t always go up easily in the command chain” of such countries.
Indeed, what David Kay called a “vortex of corruption” was a persistent drag on Iraqi WMD programs, particularly before 1991. The Iraq Survey Group suggested that Iraqi WMD efforts were “largely subsumed into corrupt money-raising schemes by scientists skilled in the arts of lying and surviving in a fevered police state.”
That would rather economically explain the both the Taepodong’s dismal record, as well as the nuclear dud.
There is another school of thought that North Korea was attempting to stretch fissile material—at least one defector report a year or so ago suggested that North Korea built a 1 ton bomb with only 4 kg of plutonium and had little confidence in the weapon. At the time, I figured there was no reason for North Korea to stretch, but maybe they had problems with reprocessing or the quality of the plutonium in the spent fuel.
The possibilities that Kim Jong Il either approved a low confidence deisgn or didn’t know the bomb wouldn’t work raise interesting questions about the much (and I think unfairly) maligned intelligence community.
I mean, the IC can tell you that North Korea’s missile can fly a certain distance or be miniaturized a certain amount beyond which either will fail, but how can the IC expect to anticipate the decisions of foreign leaders who might have less technical information about their programs and no independent advice? Or who just do plain dumb stuff?
This can get wierd: Assuming North Korea was working on an operational design, had false but high confidence in the design and we knew it would not work—how could you communicate that to US policymakers who I believe would feel compelled to assume the device WOULD work?
So why, exactly, did Russian Defense Minister Sergei Lavrov announced that the North Korean nuclear test had a yield between 5 and 15 kilotons?
Here is the data from the Geophysical Survey of the Russian Academy of Sciences. The Mb estimate is 4.0, smaller than the US estimate.
A colleague of mine offers speculates the Russian figure—which came out really early—might have been what the North Koreans told the Russians, either before the test or immediately after.
If that is what happened, then we have some reason to think they were shooting for 5-15 kt and just blew it.
One last odd fact, 5-15 kt is about what NRDC expects a low or medium skilled nuclear power to get out of 4 kg of plutonium.
Do do do do … do do do do … do-dooooooooo!
I close this discourse about operational confidence by noting that the United States has built a missile defense that does not work, to defend against a North Korean missile that does not work, that would carry a nuclear warhead that does not work.
This is all very postmodern.