Recent intelligence, including images of activity around the Punggye-ri nuclear test site, suggests that North Korea may be preparing for its third nuclear weapon test.
Indeed, senior North Korean military leaders stated on 24 January that they were preparing a 'high-level' nuclear test in part as a reaction to recent UN sanctions in response to the December 2012 long-range rocket launch. These recent alarms are another episode in North Korean provocation: why would North Korea test and why now? What are the implications if North Korea does test? And what if it does not test?
Nuclear testing for technical reasons would be plausible given North Korea's history of failed missile and nuclear performances. North Korea first tested a nuclear device in 2006. However this test was likely a flop - a 'fizzle' - as it did not produce the expected yield. The next nuclear test in May 2009 performed better, producing a yield of approximately a few kilotons equivalent of TNT, suggesting that North Korea had resolved technical errors from the first test.
North Korea stands to gain significant technical benefits from another nuclear test. It may be pursuing new weapons designs, such as developing a uranium-based weapon, as suggested recently by a South Korean government official. The December 2012 three-stage rocket that launched a satellite into orbit could equally be employed to carry a payload the same distance. Recent statements from North Korea's National Defence Commission make it clear that the purpose of the missile programme is to be able to attack the United States. North Korea may be anxious to prove that it can successfully marry its nuclear and missile capabilities.
There is, however, a potential technical reason for North Korea not to test, namely that it does not have sufficient fissile material to waste in a test. At present, North Korea is estimated to have 6-12 nuclear explosive devices.
North Korea has used nuclear and missile testing for political as well as for technical purposes. Tests are a visual reminder of the greatness of the Kim dynasty and the need for a Kim ruler, as evidenced by the timing of the April 2012 Unha-3 missile test to coincide with the centenary of Kim Il-sung's birth. Embarrassingly for the regime, the rocket disintegrated seconds after launch.
Pyongyang appears to view its nuclear weapons programme as one of the few decent cards it holds. Desiring international attention and legitimacy, North Korea uses its nuclear bombs and missiles as a belligerent bargaining chip. The regime has repeatedly bargained away pieces of its nuclear programme in exchange for Western concessions, only to rescind its commitment and return to nuclear or missile development, as occurred in the 2012 'Leap Day Agreement' with the United States.
This past behaviour suggests three factors: North Korea has not perfected its nuclear technology; it will not relinquish either its nuclear or missile programmes in the near future ceteris paribus; and nuclear weapons continue to be a priority for the Kim dynasty.
Will North Korea test again soon? If so, what would the test signify?
There are both technical and political indicators of what would be a significant test. If the Comprehensive Test Ban Treaty Organization, International Atomic Energy Agency, or national governments, detected radiological evidence of a new weapon design - specifically a highly-enriched uranium (HEU) explosive - this would show that North Korea had developed its HEU production to a point where there was enough of a surplus to carry out a test and had developed a new warhead design.
If plutonium was still the explosive of choice, this would suggest that North Korea increased its plutonium production and had built up its stocks, thus significantly expanding and developing its arsenal. Also, how North Korea tests could suggest an important shift, such as simultaneous or sequential tests, which would raise alarm bells. But the political landmarks are perhaps the most important of all.
Pyongyang is in a precarious balance between its domestic reliance on nuclear weapons for legitimacy, and staying clear of any international, particularly Chinese, red lines. Nuclear testing is subject to the laws of diminishing returns for North Korea: Pyongyang is unlikely to achieve any significant political or financial gains but stands to lose a great deal, namely the support and protection of Beijing - whose patience is wearing thin. In addition, North Korea is toying with its little remaining legitimacy as a negotiating partner, and these tests are often a technical embarrassment and therefore a domestic liability.
Alternatively, additional nuclear testing, if sufficiently planned and executed, would build Kim Jong-un's legitimacy among the North Korean military elite and solidify his leadership status, which may be in jeopardy due to his young age and lack of experience. A test would also be commensurate with North Korea's general attitude of defiance in the face of international law, but would also be a means of scorning the latest round of UN sanctions and lashing out at China for approving those sanctions.
The regime may feel that it has little left to lose and such belligerence has worked in the past. Another test would certainly be a harsh reminder of the nuclear realities at play in Northeast Asia and have implications for US allies in the region. In the meantime, much to international consternation, North Korea continues to develop, and export its missile and nuclear capabilities. But ultimately, additional testing will not be a game-changer and will not bring North Korea what it needs - fuel, food, and legitimacy.