In the days following North Korea’s inaugural nuclear test, some questions regarding the sophistication of its nuclear program were answered; however, many questions remained. Media reports indicated that North Korea expected approximately a four-kiloton detonation from its test (source). However, according to the US Director of National Intelligence (DNI), the explosive yield was “less than a kiloton” (source).
This discrepancy in expected versus actual yield as well as the small size of the detonation has led many analysts to conclude that North Korea suffered at least a partial failure in its nuclear test. Some analysts believe that North Korea may have had design flaws in the shape of the high-explosive lenses surrounding the plutonium pit; therefore, the plutonium did not properly reach critical mass during the detonation (source). Other analysts believe that North Korea’s plutonium pit may have been contaminated with impurities (source).
As a result, North Korea might attempt to remedy these problems and attempt another nuclear test; although, it is unlikely in the short-term. In order to understand whether North Korea will conduct additional nuclear tests, North Korea’s intentions as well as the technical capabilities of its nuclear program must be understood.
Intentions
Understanding North Korea’s nuclear intentions are crucial. If Kim Jong-il simply seeks a political deterrent, he may decide that additional tests are not required. While there were apparent problems with the first nuclear test, North Korea’s willingness to force its way into the nuclear club and violate international will may be enough to garner the domestic and international political capital he has been seeking. If North Korea is only seeking a political deterrent, then additional tests may not be required.
However, if North Korea is seeking a true military deterrent, i.e. a warhead capable of being mounted on a Taep’o-dong intercontinental ballistic missile, then it is likely that it will conduct additional tests. According to Michael Swaine, a senior associate in the China program at the Carnegie Endowment for International Peace, “they will want to test until they get it right.”
Capability
North Korea’s decision to conduct additional nuclear tests may be constrained by its limited supply of plutonium. North Korea likely has enough plutonium to construct between four and 13 nuclear weapons?depending on the amount of plutonium used per weapon (source). Given this limited supply, North Korea must be wary of hastily conducting additional tests without first ensuring that it has corrected the apparent problems experienced during its first test. If North Korea rushes to conduct additional nuclear tests, it may waste valuable plutonium and further reduce its deterrent capability.
Moreover, if the failure of the first nuclear test was caused by impurities in the plutonium, then it is likely that North Korea’s stockpile of usable plutonium is even more restricted; therefore, additional test would further reduce its nuclear arsenal and, as a result, its deterrent capability.