Nuclear strategy in Korea
Posted by aogSaturday, 11 January 2003 at 00:04 TrackBack Ping URL
As we face a nuclear crisis in Korea, there are a few things to keep in mind.

North Korea hasn't actually tested any nuclear devices. It's not really that simple to build a nuclear weapon, despite the scare stories you see published. While the general theory is simple, it requires some sophisticated engineering to get all of the pieces to work correctly (for instance, getting the shaped charges to collapse the critical mass). Without testing, it's not clear that the things will actually work. Note that that the US is concerned that without testing we can't be confident in our own weapons and we have much better technological capabilities than North Korea.

Even if the nukes work, how much damage will they do? There's a mythology about nukes that they are incomparably more powerful than any other weapon. That's just not the case - even in WWII the nuclear attacks on Japan were not the most deadly bombing attacks of the war. It's extremely doubtful that NK has nukes much bigger than the minimum size, about 5-10 kTons. Seoul might well be in more danger from the amount of artillery NK has massed in range than a low yield nuke. More over, if you really want to destroy a city you need to have an air burst - going off on the ground causes a lot more fallout but much less initial damage. During a war, no airplane from the North is going to make it to Seoul. Even missiles are difficult. There's a fairly narrow range of useful altitudes and a ballistic missile is going to go through it in a very short time. The nuke needs to go off between 0 and 25000 ft and at Mach3 (over .5 miles / second, slow for a ballistic missile) that's only a 10 second window. If the timer's too long the device won't go off at all. It takes very high tech to get a nuclear device to survive a supersonic ground impact and still go off. While there's nothing all that fundamental that's difficult about a timing or radar based detonator, it's like the nuke itself - the devil is in the details and without practice, it's very hard to get right the first time without a top notch tech base. Given the history of problems with NK's missiles it's not clear how much confidence we should have in their ability to deliver a nuke that works.

But here's a nasty scenario that my associate BBB suggested. North Korea has a few commercial airliners. Put the nuke on one of those and then fly it to Seoul, claiming it's been hijacked by asylum seekers. It seems unlikely that it would be shot down before it was over Seoul, at which point the nuke is detonated. This wouldn't work during war, but as an opening gambit it might be very effective. Alternatively, use a plane or a truck to drive it into the DMZ and set it off.

But we have to ask, what's in any of this for North Korean leadership? They have gotten a lot of mileage out of threatening to go postal, but actually going postal is signing their death warrants (unless they believe that China will bail them out again, which is not all that implausible). The NK leadership has consistently shown a very high regard for their own benefit so it's reasonable to expect them to do so in the future. That's why I think that the DMZ scenario is more likely. It would basically be impossible to stop and would give them at least a slim chance of conquering enough of South Korea to have a bargaining position. Nuking Seoul right off or worse a city in Japan just doesn't have a payoff that I can see but guarantees the destruction of the leadership. One may argue that they'd have to if we called their bluff to maintain credibility for next time. But it's very likely that if NK uses a nuke (especially on a city) there won't be a next time for them.

P.S. An interesting question to ask is, suppose NK fires a nuclear armed missile that impacts in Seoul and doesn't go off? What might the reaction be? Discuss amongst yourselves.

UPDATE: I failed to credit the commercial airliner trick to the original proponent, my co-worker BBB. I have corrected this error in the text.

UPDATE: A similar post showed up a few days later at Transterrestrial Musings.

UPDATE [22 Jan 2003]: Two good posts. One on cold testing where the nuclear device is tested on unenriched uranium to verify the mechanical / explosive properties. The technical help for this was alledgedly supplied by Pakistan. The other post discusses the level of corruption (high) in the North Korean military. This has an interesting correlation with an increase in the refugees [source] escaping from North Korea (which is indicative of corruption at the lowest, border guard level).