This is an edited version of a presentation made by John Everard, UK Ambassador to North Korea (DPRK) 2006-2008, to a EURODEFENSE conference in London.

1. Conventional capabilities include supplies of gas such as Sarin (used to assassinate Kim Jong Nam in Singapore). The often-quoted artillery facing Seoul may be degraded, and troops are reportedly under-trained and under-armed as nuclear and missile programmes have drained cash from other areas of armed forces. Defectors report low morale in what is mostly a conscript army.

2. Nuclear capabilities are much enhanced and improving. The 3 September blast was probably too large to be just a fission device. Originally thought to be a fission device boosted by deuterium and tritium, some think that blast may have been as much as 250ktonnes (John Hopkins University), so perhaps it was a full fusion weapon. This is important as it would compensate for targeting inaccuracies. There are limits to plutonium weapons, but DPRK has its own uranium ore mines and probably a lot of centrifuges, so it is capable of producing quite large amounts of weapons-grade uranium. It is unclear whether DPRK claims to be able to mount their warheads on their missiles are true, but a consensus is swinging towards accepting this.

3. Delivery systems are much improved. For long it has demonstrated medium-range capability.

4. Concerns now focus on long-range capability, the Hwasong 12 (3,700km to 6,000km) and 14 (6,700km to 10,000km – launched 4 July) missiles. They may well be based on stolen RD250 technology from Ukraine or Russia (there is no suggestion of Ukrainian government complicity). The launch over Japan was lofted, so did not travel full potential distance. Experts believe the missiles would have sufficient range to hit west coast of USA, or London.

The DPRK is less secretive than many think. Following through published decisions of the 7th Party Congress on 8 May 2016 (first since 1980), it can be seen that Congress decided that: "We will wage a vigorous struggle to put a definite end to the danger of a nuclear war, imposed by the U.S., with a powerful nuclear deterrence and defend regional and global peace. We will consistently take hold on the strategic line of ...... building a nuclear force and boosting a self-defensive nuclear force both in quality and quantity as long as the imperialists persist in their nuclear threat and arbitrary practices."

The DPRK MFA statement of 13 September noted this meant "establishing a practical equilibrium with the USA".
On 30 August Kim Jong Un had said that it is "necessary to positively push forward the work for putting the strategic force on a modern basis by conducting more ballistic rocket launching drills with the Pacific as a target in the future."
The statement after the 3 September test ended: "Underlining the need for the institute to dynamically conduct the campaign for successfully concluding the final-stage research and development for perfecting the state nuclear force, he [Respected Supreme Leader Kim Jong Un] set forth important tasks to be fulfilled in the research into nukes." So there must be more to come.

On 11 September the DPRK threatened that if the UN Security Council passed a tougher sanctions resolution the USA would incur "the greatest pain and suffering it had ever gone through in its entire history", and on 12 September the DPRK ambassador to the UN repeated this and spoke of "a form of ultimate means".

Where do you go after a successful long range missile launch and a successful nuclear test? The possibility of a long range atmospheric test and its effects has already been speculated upon. The DPRK might well point out that the USA conducted over 1,000 tests in perfecting its nuclear weapons, of which over 200 were atmospheric.

No negotiations seem possible. A Kim Jong Un statement 4 July, repeated frequently since, says: "The DPRK would neither put its nukes and ballistic rockets on the table of negotiations in any case nor flinch even an inch from the road of bolstering the nuclear force chosen by itself unless the U.S. hostile policy and nuclear threat to the DPRK are definitely terminated."

But US unofficial experts have explored what is meant by dropping the US hostile policy stance. There are some negotiable items (peace treaty, end of exercises), but some completely impossible (removal of US nuclear umbrella, withdrawal of US troops from ROK), effectively world-wide US nuclear disarmament.

In any case, why should DPRK negotiate? It is winning, and it is on a roll.

Will the DPRK ever use nuclear weapons? DPRK nuclear doctrine, again set out in a decision of 7th Party Congress, is: "As a responsible nuclear weapons state, the DPRK will not use a nuclear weapon first unless its sovereignty is encroached upon by hostile aggression forces with nukes....."
What is meant by an encroachment of its sovereignty? The DPRK knows that it will lose a conventional war, so asymmetrical escalation may be its only chance to survive – hence the importance of the ICBM programme. (The DPRK is alo developing a significany cyber attack capability)

What happens when the DPRK has shown it can deliver a nuclear device to a US city? It will have deterrence, but also the potential for compulsion. DPRK needs to get sanctions off its back to prevent economic strangulation and the potential for accompanying civil unrest.

There is also its long-term need to eliminate South Korea. The 7th Party Congress also decided: "We stand for national reunification by federal formula and will make every possible effort for peace and reunification. But if the south Korean authorities opt for a war, persisting in the unreasonable "unification of social systems", we will turn out in the just war to mercilessly wipe out the anti-reunification forces and achieve the historic cause of national reunification, long-cherished desire of all the Koreans."

So it appears to be prepared to use force to achieve reunification. However, the only effective force available to it is the threat of nuclear weapons, both to intimidate the South and to deter the USA.