North Korea has just carried out its sixth nuclear test, claimed to be of a hydrogen bomb suitable for fitting on a missile capable of reaching the United States. At this stage there is insufficient information to determine whether it was a true hydrogen (fusion) weapon or a less-technically demanding 'boosted' weapon, where a fission explosion is enhanced by use of light elements. Unless it is possible to detect and analyse gases released by the test, we won't know for sure. Either way, the seismic signal was almost 10 times that of North Korea's fifth test, which could make the yield around 100 kilotons, possibly more – in the range of weapons deployed by established nuclear powers.
A sixth test was not unexpected, but it will substantially increase tensions in the region. It clearly shows that confrontation with North Korea, provoking it to escalate, can only worsen the crisis. As I have argued here, and here, it is essential to engage with North Korea to explore the scope for a negotiated outcome. Last week President Trump tweeted that 'talking is not the answer!' However, US Defense Secretary Mattis subsequently said 'we are never out of diplomatic solutions'. Russian President Putin has warned that the situation between North Korea and the US is close to spilling into a large-scale conflict, and emphasised that 'provocations, pressure, and bellicose and offensive rhetoric is the road to nowhere'.
Kim Jong-un cannot afford politically to back down – unless he is offered another option, he will continue on the present path regardless of sanctions. At worst, the current US approach could lead to war. At best, it would result in North Korea continuing to improve its nuclear weapon and missile capabilities. North Korea is still some time off having a warhead it can be sure of reaching its target and detonating reliably, and requires more nuclear and missile tests, but it will get there soon enough.
The implications are extremely dangerous and far-reaching. Clearly it is unacceptable to the US, not to mention South Korea, Japan and China, to be vulnerable to North Korean nuclear attack. If the US boosts ballistic missile defence (BMD), China is likely to consider this impacts on its own nuclear deterrent and will feel compelled to increase the number of Chinese missiles that can reach US targets – an outcome hardly favourable to the US. There will be increasing pressure for South Korea and Japan to have their own nuclear deterrent, an outcome not favourable to anyone.
Some writers are suggesting the only option now is to deter and contain North Korea, as when China first developed nuclear weapons. Apart from the implications just mentioned, the real problem here is that North Korea is not a normal state with normal policies on nuclear deterrence. North Korea sees nuclear weapons as essential to regime survival, in the context of the 'lessons' learned from the overthrowing of Saddam Hussein and Gaddafi. This presents the prospect that the North Korean leadership could view an internal uprising as the act of another country (the US or China) and could retaliate accordingly. Established deterrence practice does not allow for this kind of political dynamic.
North Korea's belief that it is still in a state of war is generally not understood. The 1953 armistice did not end the Korean war – it only suspended it. In looking for a circuit breaker to the current crisis (ie, identifying what North Korea could gain that would induce it to change its behaviour), an obvious direction to explore is replacing the armistice with a peace treaty.
The key question is whether Kim Jong-un is developing nuclear weapons and missiles for deterrence, primarily against the US, or for aggression. North Korea's intentions can only be tested by initiating talks. If the motivation is deterrence, this provides a basis for a negotiated solution.
Since North Korea sees the US as its primary threat, only the US can resolve its concerns. So the US must be prepared to engage, but China's involvement also essential. Obviously South Korea would want to be involved, as would Russia – essentially this means reviving the Six-Party Talks. Initially, however, the talks would be between the parties to the 1953 armistice: North Korea, the US and China.
The most realistic approach would seem to be offering negotiations on a peace treaty, conditional on North Korea agreeing to an immediate (and ongoing) freeze on its nuclear and missile programs. A peace treaty has been a consistent North Korean demand since Kim Il-sung's time, so it is likely North Korea would be prepared to make significant concessions for this (and Kim Jong-un can present it as a major win).
In addition to a peace treaty, a parallel agreement would be required on measures to verify the freeze. It should be clear that the peace treaty will terminate if the freeze is violated. There would need to be a clear understanding of what the freeze involves. The minimum freeze, to allow talks to proceed, would be on nuclear and ballistic missile tests, and on fissile material production at the known site at Yongbyon.
A peace treaty would be followed by negotiations on a comprehensive peace settlement, covering all the issues that need to be dealt with in normalising (to the extent possible) North Korea's relations with other countries, especially South Korea. These negotiations are likely to take years, and could be reflected in a series of agreements on specific issues. An economic package would be an essential aspect, also military confidence-building measures, force reductions, and so on.
The negotiations would include denuclearisation. It must be made clear that North Korea will never be accepted as a nuclear-armed state – it must be prepared in due course to return to the NPT as a non-nuclear-weapon state. North Korea is not likely to agree to total denuclearisation until it is fully assured about its security (this could be guaranteed by the US, China and Russia, or by the P5, collectively), but progressive roll-backs should be sought.
China's security concerns are an essential factor in resolving this crisis. China has conflicted objectives, not wanting North Korea to become a nuclear threat, but at the same time wanting to preserve North Korea as a strategic buffer. China wants to avoid the chaos of a North Korean collapse, and does not want eventual reunification, when it occurs, to result in US forces on its borders. On the other hand, the current situation guarantees that the US will remain militarily engaged in the region, and China is especially concerned about BMD deployment in South Korea. Thus China has strong incentives to do more to influence North Korea.
At the earliest opportunity the US should engage with China on these concerns, to reach an understanding on the future status of the Korean Peninsula under a range of possibilities (eg continuation of two states, a confederation, re-unification). It is likely a force limitation agreement, with verification/transparency measures and maybe a substantial demilitarised area, will be required.
If North Korea refuses talks, or violates agreements reached, containment of North Korea with growing nuclear and missile capabilities is not a sustainable option. As I've mentioned, the regional security situation will become increasingly unstable and dangerous. It is essential to show China that cooperation in maximising pressure on North Korea is very much in its own interest. If Kim Jong-un cannot be persuaded against escalating this crisis, others in the North Korean leadership may conclude that the principal danger to the regime's survival is Kim Jong-un himself, and act accordingly.