Martin Hellman’s take on the risk of nuclear war

I’m sure some of you have already seen it, and I know I am late to the party as both marginalrevolution and freakonomics have already mentioned it and linked to it, but I never got around to linking to it from this blog, even if I found it somewhat interesting when I watched it more than a week ago, a mistake I now shall correct:

Even if the title of the presentation/video is: “Soaring, Cryptography and Nuclear Weapons”, he spends probably 45 minutes talking about nuclear weapons, so that is really what the whole presentation is about. The first 8 minutes or so on soaring is related to his talk on nuclear weapons, and I would advise you to watch it all. You can read a paper closely related to the talk here, if you prefer a written version from a video and don’t have an hour to spare (you should be able to read the paper in a significantly shorter amount of time than it takes to watch the presentation).

A few selected main points:

i) Problems related to high impact low probability events are easily overlooked and/or ignored due to ie. framing and status quo bias (that’s just another way to state what he’s trying to say in the beginning with his 99,9 % safe maneuver).

ii) You need units of time on your risk assessments. And not only because risk factors change over time. The concept of compounded risk is important, and often overlooked.

iii) Status quo bias is very important when explaining the nuclear policy of countries with nuclear weapons. As Hellman states about the US experience: Even minor changes in our nuclear weapons posture have been rejected as too risky even though the baseline risk of our current strategy had never been estimated. (what does this argument, if it is valid, btw. tell us about the sustainability path of the current state of affairs in the long run?)

…which leads us to…

iv) This risk is not well understood, and very difficult to assess – and nobody really seem to care about it much.

v) There are many different ways nuclear weapons can be used today, both when it comes to warfare and -terror. Some scenarios lead us to a state we can return from again; others do not. Close monitoring of early warning signs is critical when it comes to risk assessment and -prevention of this problem.

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The recently conducted North Korean nuclear weapon test was one of the warning signs mentioned above, and it sure as *** did not decrease the risk of nuclear weapons being used somewhere in the future.

More general comments: I would say I think Hellman overestimates the risk, but I’m also pretty sure I think most people underestimate it, and/or don’t think about it at all. Also, I’m not so sure this risk is either as assessable or as preventable as Hellman believes. But, I must add, I do not think that the fact that the risk is not easy to properly estimate, is a weighty argument against trying much harder than we do today to do so. Last, compounded risk is important, but it’s also a problematic concept to use when forecasting and designing long run estimates, precisely because risk factors change a lot over time: The risk of nuclear war was zero 80 years ago, but that fact is irrelevant today. Yes, you can weigh the data in the model so that risk in recent periods weigh higher than risk many decades ago, but it’s not clear that this is the best approach (in a crisis, a near miss 40 years ago would provide better information on how to act – or on how not to act – during the crisis than the risk assessment ten years ago, and the actions undertaken then, where nothing out of the ordinary happened) – maybe it would be better to weigh annual data according to the risk of the specific year, so that the actions undertaken in relative high-likelihood neighborhoods (near-misses) will be better taken into account? Maybe a combination, and maybe seven other variables should be included? No matter how you weigh the data, you’re gonna have problems knowing what to do in a bad situation, even if you knew the proper risk model and distribution of the data, which you most certainly don’t. If people don’t think long and hard about this before something ugly pops up somewhere down the line – and the default position here would probably be that the fact that some people did think long and hard about this for some time would decrease the chance of “something ugly” eventually popping up – there’s a lot of stuff that needs to be done in a very short amount of time, and that is a recipe for disaster. As Hellman makes it clear in his presentation, the “do/think-very-little” seems to be the current state of affairs, seeing as no one so far has even made an attempt to quantify the risk we’re facing.

Oh yes, one thing I forgot: In my mind, the risk of nuclear weapons being used is not on a path of uniform motion, where the absolute risk of one or more nuclear bombs being used somewhere increases over time at a steady pace, whereas the annual risk is fixed. I think the absolute risk in the long run is accelerating, that is, the risk of a bomb going off increases over time and gets bigger every year. This is related to the fact that I do not consider the most relevant metric, when it comes to the risk of a nuclear bomb being used, to be the number of weapons available in the world, but rather the number of relatively autonomous agents each having at least one – and that number has only gone up since the first nuclear test was conducted.

One more argument why global warming doesn’t concern me all that much…

This post is primarily to those people who think global warming is a really big problem, by far the biggest one out there. To those people who think that “something must be done, now!” Others are of course allowed to read along as well…

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In 1945 only one country possessed nuclear warheads. Today the number is 9.

A lot of people like to think that nuclear weapons are never to be used again in warfare. We’ve seen the consequences and we didn’t like what we saw. I see a lot of problems with this approach:

i) Warfare has an ugly tendency to become asymmetric as it proceeds. In the short run asymmetries are allowed but not in the long run. If warfare is asymmetric over the long run, the war is over, so in most wars, the ends tend to justify all means. To state this another way, once the first bomb has exploded, the costs of using the nuclear arsenal as a retaliatory measure decrease rapidly.

This reasoning of course not only increases the risk that (multiple) nuclear warheads will be used in future wars, it also increases the likelihood that states would want nuclear warheads in the first place.

ii) Human memory is short. Quite a few people said “never again Hiroshima” after the War. How many actually concern themselves with this issue today? Has the risk decreased?

I think not. If we assume that

a) d[P(war involving nuclear weapons)]/d(#countries possessing nuclear weapons) > 0 and
b) d(#countries possessing nuclear weapons)/dt > 0
then it follows that
c) d[P(war involving nuclear weapons)]/dt > 0

Are these assumptions valid? What about MAD?
I think they are valid in general. An analogy might be in place: The “real world” is more likely to look like the perfect competition model when, all else equal, we increase the number of firms. Because collusion basically gets harder when you add more firms; it’s a lot easier to come to terms with one competitor than it is to make an “implicit” deal with ten (MAD is from this point of view basically just an implicit collusive agreement between states intended to decrease the risk of nuclear war).

iii) All analyses made today will be biased by, in retrospect, stupid ceteris-paribus considerations and status-quo bias. Imagine a situation where the Red Khmers had had access to a lot of nuclear weapons. Hitler. Or Mao. Mao especially deserves mentioning because we know a little about what he thought about this issue. The 17th of May 1957 he said in a speech at the Chinese Communist Party Congress:

“There’s no reason to be concerned about a World War. The most that can happen is that people die [...] Half the population is exterminated – that has happened not a few times before in China’s history.”(*1)

Mao worked very hard to get those warheads, but fortunately without much success. It deserves mentioning that “half the population”, as he put it, at that time was 300 million people.

300 million people.

If assumptions a and b are correct, the likelihood that a madman like Mao will obtain nuclear weapons increases over time, and sometimes it only takes one madman to start a very bad series of events – just ask Gavrilo Princip.

iv) Scale will always be an “issue” when considering proliferation, and we will not see mass-production that will drive down the costs of nuclear warheads to that of conventional arms anytime soon. But as more and more governments obtain nuclear weapons, the likelihood that private agents get their hands on one of these weapons increase. Also, I doubt this effect is linear.

It seems fair to assume that as the #of governments possessing nuclear weapons increase, the likelihood that non-state agents obtain a warhead increases likewise. Not only because of corrupt regimes that sell off nuclear material to third-parties. But also because of i). The very strategic elements involved considering governmental use of these weapons give governments that want to use these weapons without paying for it an incentive to use private agents to do their own bidding. By using private agents, the diplomatic costs of using nuclear weapons decrease. Which means that governments wishing to use their arsenal will have a problematic incentive to spread the weapons as much as possibly to private agents (/terrorists) in which they trust.

v) A related problem to that of non-state agents is that of retaliation under this scenario, which is of some importance. If in 50 years a Hindi terrorist bombs up Islamabad, will the Pakistani government wait a long time to figure out where the weapon came from? Maybe, but I’m sure no matter what the government would decide, it could be deemed rational. That’s the problem with game theory’s explanatory power – the same initial conditions can easily result in multiple equilibria. The point is – even if governments are behaving rationally, and we throw away the idea that persons, not states, are important here, it’s very difficult to know what a government will do if it is attacked. Rationality is not in itself an argument in favor of non-application of nuclear devices, it surely needn’t be, primarily because of i). Bounded rationality sometimes looks woefully irrational to the outsider.

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(*1): The quote is from “Mao, the unknown story”. I own the Danish translation of this book and the English version of the quote given above is thus my own translation of the Danish version.
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An interesting post related to the subject treated above btw. is this one.

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All the above said, I rate the risk of nuclear war in a WW-III scenario quite low, even if perhaps not as low as most people. This is not the point though. The point is that I could have written a post like this about perhaps a dozen subjects. Why is global warming on the top of your list of priorities? Have you thought about how the earth would look after a global nuclear war? Do you have a very good reason for making global warming your “cause” – or have you just picked “global warming” as your great concern, and not “nuclear proliferation”, because it’s a popular thing to do? Is your concern just a signal that you care, or have you really thought long and hard about what “cause” you thought it was most important to support? How many alternatives have you considered?

In short: Have you thought this through?