North Korea’s Next Move: Tactical Nuclear Weapons and a Window of Vulnerability?

Following North Korea’s September 3 test of a hydrogen bomb the United Nations Security Council has placed further economic sanctions upon North Korea, and analysts have since focused on what Pyongyang might do in response to them. North Korea itself has promised some type of reaction, there’s plenty of precedent suggesting some response is to come, and those promises have been accompanied with super charged rhetoric especially with regard to Japan.

So far as I can surmise analysts have tended to identify three possible North Korean responses. The first, a standard trajectory test of the Hwasong-14 ICBM, once again “over flying” Japan, taking the form of a further reliability test of the missile and, moreover, a combat conditions test of the ICBM re-entry vehicle. North Korea could launch the Hwasong-14 on a standard trajectory and cut off the engines early to lower the range, especially if launched in the North Pacific. I suspect that North Korea might prudentially head more south, that is away from the continental United States for a standard trajectory ICBM test.

Secondly, North Korea could give us some look at the Hwasong-13 ICBM, most likely the ICBM to deliver the hydrogen bomb. That could take the form of a photo-op, a static hot fire test of a cluster of Pektusan (or March 18 revolution) engines or maybe even a lofted trajectory test. Thirdly, North Korea might conduct a nuclear test. Some have suggested this could even take the form of an atmospheric test of a nuclear warhead launched by a ballistic missile, say the Hwasong-14 or Hwasong-12. Perhaps, by contrast, a nuclear test could take the form of a lower yield test at tunnels accessible from the South or West portals at the Punggye-ri nuclear test site.

Let me make, briefly, some remarks regarding the last of these namely a lower yield nuclear test. Recent satellite imagery from Punggye-ri shows heightened activity at the South and West portals. Tunnels here can contain nuclear explosions with yields much less than at the North portal; the overburden for the West tunnel is reported at 490m. A report carried by KCNA (from a major North Korean newspaper i.e. Rodong Sinmun) stated

The U.S. will receive more big or small “gift packages” if it persists in hostile policy toward the DPRK

What could “small” gift packages refer to? It could refer to nuclear tests of yield less that the September 3 hydrogen bomb test. We know that North Korea has conducted five nuclear tests of much lower yield than the sixth test, with the fifth likely having a yield of 35KT. A good point made by Siegfried Hecker, the former director of the Los Alamos National Lab, is that North Korea’s nuclear testing programme, unlike India’s and Pakistan’s, has been slow and methodical. One could argue that tests 1,2,3 and 4 were meant to build up to tests 5 (standardised boosted fission warhead) and 6(standardised two stage thermonuclear) in which tests 1,2,3 and 4 are not reflective of an actual nuclear warhead.

A “small” gift package, to be tested at tunnels accessed via the South or West portals, could turn out to be tests of tactical nuclear weapons.

Should that be the case these “little” bangs would have just as much significance as the “big” bang of September 3.

Consider. Most discussion on the parameters of a potential conflict with North Korea always end with the refrain that North Korea would surely lose. To be sure North Korea can inflict much pain, but eventually order would be restored to the galaxy as it were. However, could it be imaginable that North Korea might seek to develop a winning strategy? Let us assume that in the initial hours and days of a conventional conflict North Korea has taken whatever remains of Seoul and large chunks of South Korean territory to the south of the DMZ. Doubtless, US and South Korean military forces will mobilise to launch a large scale combined arms counter attack with the view to enveloping Pyongyang and ending the North Korean regime.

However, low yield tactical nuclear weapons, much like with NATO planning during the cold war, could be used to breakup large concentrations of armour, infantry and artillery so thus thwarting any counter-attack. That would be much akin to Pakistan’s response to India’s reported “cold start” doctrine. Nuclear armed ICBMs with boosted fission weapons and two-stage thermonuclear weapons, targeted at the United States, could be deployed as a type of intra-war deterrence preventing US nuclear escalation and locking in North Korean military gains. Such a scenario would be a real test of US extended deterrence.

That is to say, the combination of battlefield tactical nuclear weapons and nuclear armed ICBMs would present a “window of vulnerability” much like the, fake it must be said, “window of vulnerability” that Soviet large throw-weight ICBMs were said to pose during the cold war.

It is easy to imagine how battlefield tactical nuclear weapons would make a lot of sense for the North Koreans, and why their use could well give North Korean strategic planners a means to develop a military strategy, or claim to Kim Jong-un that they have one, aimed toward preventing what everybody assumes to be an inevitability namely North Korean defeat.

I write this on the fly. Apologies for sloppy errors and lack of detail. Also what is said above is speculative and should be seen as such; note frequent usage of “could.” I hope to say more regarding some of these themes in the coming period.