I doubt it was a suitcase nuke

I was hoping to write something by now, but haven't had time.  That's ok; this article is very well-written and says what I would have said anyway.

It's not that "suitcase" nukes never existed.  Small, portable nuclear devices have been around for decades.  The U.S. military has 0.5 kT nuclear devices which can be loaded into and fired from a 105mm cannon.  One person can move and use them with ease.  Problem is, making them work when they are this small (this small physically, not this small in terms of output) is not an easy thing.  The level of sophistication is orders of magnitude higher than would be necessary to produce a bomb of the same explosive yield but much larger physically.  And keeping them functional is also problematic.  Radioactive materials have a half-life.  That means they change from one element to another over time.  After a while, fission-material like plutonium becomes stable-material like lead.  When you are dealing with a crude bomb that has a low yield for its physical size, you can get away with having a lot of stable-material "contaminating" your fission-material fuel.  But the higher yield per pound you try to achieve, the more purity becomes a factor.  The artillery nukes need to have their fuel replaced about every six months, or they don't function.

But, what about a fizzle?

That's a real possibility.  The NorKs could have been aiming for a much larger blast.  We just don't know.  This is where intel will come in.  Were they trying to "make a statement to the world" by setting off a big bomb?  Were they disappointed with the result?  Or were they simply doing a test of production process on a small scale?  Did they get a good result, one which will encourage them to proceed with a large scale production?

This is why we need SPIES.

More later...

Comments

[Patrick Joubert Conlon]

Seems it was a dud.

[Gullyborg]

Actually, that is impossible to tell without some ground intel. We can tell you all sorts of things about the size of the blast via tech intel from across the globe. But we have no clue what the NorKs were actually trying to produce. We need some humint (human intelligence, for you in Palm County) giving us information about what's going on inside the NorK government, to determine if this was a dud or not.

There are 3 possibilities, ranked in order of severity.

Least severe:

It was a dud. This is still a problem. A dud bomb is still an order of magnitude bigger than any conventional bomb. This blast could have wiped out the entire financial district of NYC. It is also dirty, in the fallout sense. In terms of radiation, a dud bomb is actually far more dangerous than an efficient one, because a dud will spread a huge amount of pure plutonium over a distance. Pure plutonium, even in tiny amounts, is one of the worst poisons a person can ingest. And a dud bomb will spread it in vapor form across a population center. When you hear about a "dirty bomb" as a terror weapon, what you are basically hearing about is a "dud" nuclear weapon. Nuclear weapons need a lot of periodic maintenance in order to remain operational. The nuclear fuel must constantly be replaced with "fresh" fuel. A 30 year old ex-Soviet warhead that has not been serviced in a generation, something that we fear could have wound up in a terrorists hands after the Soviet break up, is a perfect dirty bomb. When it goes off, it will make a really big boom by conventional bomb standards, but far worse it will spread deadly debris all over the place and could make an entire city uninhabitable for years. Now, I doubt NorKs would be trying to design and test a "dirty" bomb, because all they would really need to do is take a "good" bomb and let it sit for a while. But assuming this was a "dud" resulting from a flawed program, it is still an extremely bad thing. If they can reproduce this same dud, they still have a very nasty terror weapon.

Moderately severe:

This was not a dud, but a small-scale test. Plutonium is a precious commodity. There is no reason to use enough to produce a 20kT explosion in a test if you have sufficient confidence that a small-scale test will confirm your design. If this is the case, and it is very possible, then it means the NorKs have a functional design. They just don't feel that they have enough plutonium on hand to invest in full-scale testing. This is very bad, because they have a working design. But at least we have some confidence that their production capability is limited. This means they probably aren't mass producing warheads. Yet.

Worst case:

This was not a dud or a small-scale test, but a full-scale test of a sophisticated tactical "battle field" nuke. As I have said elsewhere, the U.S. developed 0.5 kT nukes capable of being fired by field artillery. They could also be deployed by small rockets carried by a single-engine fighter plane. The purpose of such a nuke is not strategic deterrance. It is a battlefield weapon. It could be used to wipe out a single military encampment or an advancing division. The intention is to deliver massive damage to an enemy in the field without launching the sort of "first strike" that would normally result in Mutually Assured Destruction. Because it isn't being used to wipe out cities, the target nation doesn't have the same socio-policial will to respond with strategic nuclear strike. This is a weapon produced with the mindset that you can USE nuclear weapons in a war and WIN, without wiping out half the planet.

This is the type of weapon that North Korea could use to launch a tactical strike against the forces massed against the DMZ in anticipation of an invasion of South Korea. It is the type of weapon they could use to wipe out a harbor of ship in, say, Japan, to hamper American intervention. This is exactly the type of nuclear weapon that Kim Jong Il would think could allow him to start a war of aggression and win it. And as long as America is politically unwilling to respond with a full-scale nuclear assault, he may be right.

Imagine a President like Al Gore faced with the decision: launch a full-scale nuclear retaliation, or let North Korea assume control of South Korea and Japan. Think he'd have the balls to strike? Or would he be too concerned about the environmental impact?

Fortunately, as I said, these are sophisticated weapons. It is very difficult to make functional weapons small enough for battlefield use that will work as planned. It is easy to make a physically large weapon with a blast small enough for tactical use. But the physical size of the weapon makes it impossible to be launched in a manner suitable for rapid deployment against changing targets. To make the device small enough to be launched by mobile artillery or a single-engine figher jet takes a level of sophistication usually not found outside of a superpower - especially not in a fledgling program.

But it is a possibility. And a very, very scary one.

Now, more than ever, we need to redouble our efforts to get humans inside the NorK government.