From time to time we hear from conservative hawks, both within and without the Trump administration, that North Korea does not have a nuclear weapons programme to deter the United States, rather, North Korea seeks a strategic capability to compel the reunification of the Korean peninsula on Pyongyang’s terms. That’s why we need to engage in a “preventive” strike on North Korea’s strategic capabilities before Pyongyang rolls the dice, for such a war of reunification is highly likely and its likelihood grows with the growth of North Korea’s nuclear capabilities.
However, when one examines the nature of the North Korean nuclear programme, as it currently stands, one finds that the empirical evidence does not support that charge. Indeed, it is interesting to compare North Korea’s nuclear programme with Trump’s draft Nuclear Posture Review, supported and drafted by strategic hawks, leaked earlier in the month.
As we know the “Super” or hydrogen bomb was developed despite the advice of the General Advisory Committee of the Atomic Energy Commission, chaired by Robert Oppenheimer. The GAC advised that the US should concentrate on developing fission weapons, especially for tactical use on the battlefield by the Army. Although controversy over the development of the Super cost Oppenheimer his security clearance, and led him to becoming, undeservedly, a type of anti-nuclear folk hero nonetheless in the end the United States both built the Super and produced an array of tactical nuclear weapons. The simplest explanation for this is that it could do both, so did do both.
Many, but not all one should add, of those tactical nuclear weapons, such as warheads for short range surface to surface missiles, gravity bombs, artillery, recoilless guns, and the man portable special atomic demolition munition, were low yield. We tend to associate, therefore, tactical use of nuclear weapons in the operational context of land warfare with low yield weapons of such type most especially.
Should North Korea be developing nuclear weapons to augment the operational capabilities of its ground forces, given US and South Korean conventional technological superiority, it would be following the advice of Oppenheimer’s General Advisory Committee. That is, the emphasis would be on tactical nuclear weapons not the Super.
To defeat South Korean forces, and US forces in theatre, the Korean Peoples Army would need to negate their capability to engage in large scale, at the operational level, combined arms manoeuvre warfare. Tactical nuclear weapons can be used to strike concentrated armour, combined arms formations, and air bases crucial to manoeuvre warfare. In a battlefield environment characterised by tactical use of nuclear weapons the idea would be to deny the enemy usage of its conventional forces to engage in enveloping operations whilst preserving your own capability to do so. In this way, one may argue, North Korea could seek to compel the unification of the Korean peninsula on its terms through offensive war.
Putting aside all the human, diplomatic, political, and economic costs associated with such a scenario North Korea’s observable nuclear programme isn’t reflective of such a nuclear war fighting doctrine. The culmination of North Korea’s nuclear programme, thus far, has been the two-stage thermonuclear weapon tested in September 2017 and the large throw weight Hwasong-15 ICBM.
A two stage thermonuclear weapon, tested according to most commentators at the threshold test ban treaty limit of 150 kilotonnes, but I would argue higher (Sigfried Hecker in a recent talk at Los Alamos stated in a ppt slide possibly up to 250 kilotonnes but I suspect higher still more like 350kt), for a large throw weight ICBM is reflective of a nuclear strategy built around countervalue, or city busting, nuclear deterrence. Some have argued that the large throw weight of the Hwasong-15 reflects a desire to MIRV the payload, however the accuracy of the Hwasong-15 precludes its use in a MIRVed counterforce, or nuclear war fighting, context.
North Korea’s incremental testing programme, it seems, has given Pyongyang the capability to develop a standardised and relatively low weight boosted fission warhead (35 kilotonnes) and a two-stage thermonuclear warhead. Estimates of the throw weight of the Nodong medium range missile put it at about 800kg, and the Scud-ER at 500kg. The Pukguksong-1 and 2 solid fuelled MRBMs appear to reflect concerns regarding survivability, and penetrability with reference to ballistic missile defence (esp THAAD in region), rather than with tactical use on the battlefield. These throw weights, in addition to the throw weights of the Hwasong-15/14/12, and the matter of survivability, suggest a concern with deterrence not tactical/operational warfighting in support of ground forces given that they appear to accommodate, at the very least, the standardised boosted fission warhead (35kt) in the case of the Nodong and Scud-ER. Furthermore, the Nodong and Scud-ER are not accurate enough for tactical use by low yield warheads.
Irrespective of yield the images we have of the boosted fission device and the thermonuclear weapon support the contention that these are devices for delivery by North Korea’s current missile forces, which as noted are not accurate enough for precision strikes.
Contrast this with Trump’s draft Nuclear Posture Review. As I have commented previously, its guiding doctrine is tailored deterrence which really is a justificatory discourse for Reagan era ideas regarding intra-war deterrence which is a nuclear war fighting doctrine. The three additional modernisation items, additional to the generous Obama era nuclear modernisation programme, earmarked in the draft NPR consists of a low yield nuclear warhead for the Trident D-5 SLBM (a type of nuclear prompt global strike), a nuclear armed sea launched cruise missile, and an intriguing delay in the retirement of the B83-1 gravity bomb (not low yield). The idea here is to give the President more useable nuclear attack options, especially in regional contingencies of the type that would involve a state such as North Korea. I suspect that, regarding Northeast Asia, an important concern here are perceptions about the credibility of extended deterrence. The B83, though high yield, might be relevant here, in ways that I shall explore in a separate posting.
So, there we have it. North Korea’s nuclear weapons programme is built around deterrence and Trump’s nuclear weapons programme is built around nuclear war fighting. Yet we consider the former, not the latter, as the leading source of nuclear danger. We might do well to reflect on that assumption rather than simply take it for granted.