The CIA has reportedly confirmed what’s been rumored for months: last year’s nuclear test by North Korea was, in fact, a flop.

According to Reuters, CIA Director General Michael Hayden described Pyongyang’s nuclear test as a failure and said the United States does not recognize North Korea as a nuclear weapons state. Hayden made the comments on Tuesday, during a meeting with South Korea’s Defense Minister, part of a visit to U.S. allies in the region.

Before reading too much into this report, a word of caution is in order. The Reuters disptach is based on an article in a South Korean newspaper, which got its information from a ROK defense official. Officially, the South Korean MOD has refused to confirm Hayden’s comments, as has our embassy in Seoul. The Korean publication that broke the story–JoongAng Ilbo–is one of the “big three” papers in South Korea, with reliable access to government officials and information. While no one seems willing to verify General Hayden’s assessment, the lack of confirmation suggests two possibilities: (a) the Director’s remarks weren’t intended for public release (at least not yet); or (b) the story was a deliberate media plant, designed to reassure a nation that has the most to fear from North Korea’s nuclear program, while granting Hayden a measure of deniabilit. My money is on Option B.

As we reported last October, Pyongyang’s first nuclear test was a giant fizzle by any standard. Post-blast analysis suggested that the DPRK device had a yield equivalent to only 200-400 tons of TNT, perhaps only 5-10% of what they hoped to achieve. That made North Korea’s first nuclear bomb a veritable pop-gun; by comparison, the first U.S. atomic bombs (dropped on Japan in 1945) had a yield of 10-20 kt; nuclear devices detonated by India and Pakistan in the late 1990s had yields in the range of 5-10 kt. At the other end of the scale, “modern” thermo-nuclear weapons in the arsenals of the U.S., Russia, China, France and Britain have explosive yields measured in the hundreds of kilotons, or even megatons (one megaton equals one million tons of TNT).

Technically, the reasons for North Korea’s apparent failure remain unclear. However, there are a number of factors that might have prevented a successful test, as one of our readers pointed out last fall:

“An accidental 4 KT yield could come from a large mass of fuel that doesn’t get held together long enough for more than a few ‘links’ of the chain reaction – because of weak metal alloys, or poor conventional shaped charge design or manufacture, or poor fuse design or manufacture. Or even if the bomb design & manufacture were good, the fuel could be contaminated such that neutrons are either absorbed too frequently by an impurity, or released too frequently by a fuel ‘hotter’ than the design. NONE of these are trivial problems to solve. And the smaller the fuel mass employed, the more sensitive the whole process becomes. Big bombs (20 KT) are hard; huge bombs (200 KT) are harder; small bombs (2 KT) are really, really hard to make.”

Obviously, the test failure was a major reason behind North Korea’s decision to return to the Six-Party talks late last year, and its subsequent agreement to shut down its Yongbyon nuclear reactor. Obviously, a marginally-reliable nuclear weapon isn’t much of a negotiating chip, so Pyongyang was suddenly willing to cut the best deal possible, getting rid of an aging nuclear facility, in exchange for desperately-needed energy assistance.

Despite the apparent problems in North Korea’s nuclear program (and the recent diplomatic success in Beijing), it is far too early to write off the DPRK’s nuclear ambitions. Most likely, Pyongyang still has some sort of covert development program–the same track that was used to continue weapons research after the 1994 “Agreed To” framework. Continuation of the covert program would allow North Korea to resolve technical problems evident in last year’s test, while “publicly” abiding by the most recent agreement, and receiving energy aid from the west. Once the technical issues are solved, Pyongyang would start complaining about the current accord, find a pretext for abandoning it, and follow those acts with another–and possibly, much more successful–nuclear test.