Geoff FordenDesigning Iran’s ICBM from the Ground Up

Click on the image for a larger view.

Regular readers of the wonk will know that I originally thought Iran would have invested its initial time and effort in developing a new, more energetic, propellant rather than a new thrust vector control mechanism or, at the very least, do both in parallel. They may very well still be working on higher-energy propellants but I feel, after preparing for these posts, that I understand a lot better what they hope to accomplish with the path they have chosen for the Safir. Interestingly, after searching for all the openly published research papers by Iranian rocket scientists that I could find, there are many more related to clustering twin engines than in, say, UDMH. Unfortunately, that only seems significant after we’ve seen the twin engines of the Safir second stage. (My feeling is that openly published research papers are good for finding organizational links but not for determining directions of research since important efforts might be classified. But that is a story for another post!)

Sizing the Missile Yesterday, I discussed how Iran has assimilated the technology for liquid-fueled missiles by first purchasing a complete factory for manufacturing Nodong missiles and has now moved on to improving that technology by indigenous innovation. Today, I want to “design” an Iranian ICBM (which I call the IranCBM) and see just SCUD-type technology can take Iran. This is done graphically by a method discussed in many books written in the 1950s and 60s, which are usually the best for understanding missile proliferation today. I have compiled the data for the following graphs from “Flight performance Handbook for Powered Flight Operations” edited by J. Frederick White:

Click on the image for a larger view.

The graph on the left can be used to determine the “effective” velocity required at launch to deliver a warhead to a given range for a minimum energy trajectory. This includes the effects of atmospheric drag as well as the losses in speed due to gravity; “fast” missiles lose more energy passing through the atmosphere while “slow” missiles lose less. As we shall see, an Iranian ICBM is going to be a relatively slow missile. That implies that the missile must be capable of producing an effective launch velocity of 8.3 km/s. This is, of course, much higher than what we think of as the velocity needed for a 10,000 km trajectory, and in fact it is much higher than LEO orbital velocities. But, again, the “excess” is lost during the passage through the atmosphere and to gravity.

That information is used in the graphs on the right which show a two-stage launch vehicle’s gross weight require to move a 750 kg warhead 10,000 km as a function of the average deadweight of the missile. (Two stages because that appears to be the number of stages the MDA has focused on for the “Projected Iranian ICBM by 2015” that I discussed yesterday. A 750 kg warhead seems to be possible if Iran really did get the design for a 500 kg nuclear explosive.) I originally drew a line across corresponding to a weight of 119 tons, the absolute maximum four Nodong-type engines could lift in the first stage. At the time, i.e. before doing the analysis, that made a lot of sense to me. It would not require Iran to develop and new, more powerful engine and therefore seemed to be the quickest for them to build. I also assumed a higher specific impulse for the first stage (240 s) than the widely accepted value for the Nodong/Shahab (232 s). That could be due either to replacing the jet vanes with gimbaled engine-based thrust vector control or switching to a new, higher energy propellant, or perhaps both. One effect of designing this missile graphically, however, has been to approximate the missile as having a constant specific impulse and the same deadweight fraction for both stages. That’s the sacrifice I made for having a method easily presentable in a blog!

It turned out, however, that using four Nodong engines seriously underpowered the missile! It produced a missile that spent too much time fighting gravity and only flew about 5,000 km. But that is jumping ahead!

What does the resulting design look like? The overall weight of the missile, as can be read off from the graph on the right, is 120 tons regardless of what fuel and oxidizer are used just so long as they have a specific impulse of 240 s. Assuming a propellant mix of RP-1/IRFNA, produces a first stage 2.5 m in diameter and 15.4 m long. The same propellant mix for the second stage yields a diameter of 1.25 m and 12.3 m, which includes 2 meters for the engine and guidance system. Adding 1.5 m for the warhead yields a total missile length of 29.2 m, the height of a 10 story building! (I have included a GUI_missileFlyout model of the IranCBM in the comments section. You can download a copy of my program for simulating ballistic missiles at ! It’s free and its really cool! (Or at least I think so.) This graphical method of designing a missile is full of approximations but the GUI_missileFlyout simulation, which also uses some approximations, only less so, shows the resulting design achieved a range of over 9100 km; something I consider a success!)

This is almost a third again as long as the Safir space launch vehicle and yet Obering shows these two missiles almost exactly the same height. One possible answer is that a nearly 30 m long missile, weighting 120 tons will take Iran a long, long time to develop if it uses SCUD-type technology. It represents a threat that is far from imminent, something that is not in the Missile Defense Agency’s interest to show.

Just how long would it take Iran to develop the IranCBM? One of the key facts is that Iran will need to develop a new, very powerful engine for the first stage even if it sticks with SCUD-type propellants. Four Nodong engines, even with their own custom turbopump, are simply not powerful enough for this mission. Iran would have to develop a cluster of engines with the equivalent power of ten Nodong engines. They would also have to develop a turbopump to feed the cluster of newly developed engines. While I have not been able to identify the engines used on the Safir second stage, it seems likely that they were developed for a different missile (one Wonk-read has suggested the second stage engines for the R-27, though I cannot tell from the pictures I’ve seen). If so, Iran has no history of developing its own engines or turbopumps; the Safir almost certainly used a SCUD turbopump. Finally, Iran would also have to finish the development of thrust vector control using gimbaled engines that it started with the failed Safir launch on 17 August 2008.

I have a hard time believing that Iran has enough skilled manpower to develop these two missiles (the Safir and the IranCBM) concurrently. Iran’s guidance and control people must all be very busy developing the Safir’s control systems, which is, after all, a test bed for the IranCBM. To take full advantage of that experience, the same people developing the Safir should also be used to develop the IranCBM. If I use the date of the first publication (early 2007) for controlling the fuel mixture for twin engines, and add a year for them to have worked out the details before the paper was published, I get a starting date for the Safir (a bit simplistic, I agree) of 2006. Then, adding another year and a half from now for them to successfully develop the advances the Safir represents, I get a total development time of four years. So the guidance and control development for the IranCBM could start at the end of 2009.

It’s possible that Iran has already started to develop the new first stage engine, assuming they were willing to take on such a large and daunting project as the first engine they develop. (There are rumors that Iran has received an SS-N-6 missile or missiles from North Korea. If so, even those engines would be far too underpowered to drive the IranCBM.) But as far as I know, there is no indication that Iran has a sufficiently large test stand to develop an engine with a 300 ton thrust, much less a cluster of four of them. Such a facility would be extremely large and would be visible in satellite photos. Do any of you, gentle readers, know of such a facility? Developing such an engine is considerably harder than the Safir second stage. Perhaps twice as hard? Would it take Iran twice as long to develop just the engine? Perhaps eight years?

There is still much more for Iran to do For one thing, they would have to be developing the production line for the much larger diameter first stage. They could, of course, have already started this using the trained manpower from the Nodong factory. This would mean, of course, that the Safir development might be slowed down unless they recycled deployed Shahabs as first stages for the Safir in the rest of its development flights. These are all part of the program risks associated with concurrent development and production. For an excellent discussion of these problems in US weapon system development, see the CBO paper “Concurrent Weapons Development and Production” (1988) by my friend Wayne Glass.

I think even eight years sounds optimistic considering Iran’s known state of development but even that would be considerably longer than Obering’s 2015. And a more realistic estimate might be sometime beyond 2020 and that assumes that Iran has made the strategic decision to develop an ICBM capability; something that is not a logical consequence of the Safir space launch vehicle development.

This finishes this particular experiment in blogging: a series of techno-wonk posts that explores an issue in what some might feel is way too much detail. Hopefully, if Jeffrey hasn’t become totally disillusioned with me, I will return but, take heart, I don’t have any more plans for a new series!


  1. Geoff Forden (History)

    Here is the GUI_missileFlyout Model for the missile designed here:

    <?xml version=“1.0” encoding=“utf-8”?>
    <missileParameters>2.000000e+000 4.101050e+000 2.050525e+000 0.000000e+000 2.400000e+002 2.400000e+002 0.000000e+000 6.400000e+001 1.430000e+002 0.000000e+000 2.112028e+005 4.067529e+004 0.000000e+000 2.112028e+004 4.067529e+003 0.000000e+000 1.653467e+003 0.000000e+000 0.000000e+000 0.000000e+000 0.000000e+000 1.000000e+009 0.000000e+000 0.000000e+000 0.000000e+000 1.000000e+009 0.000000e+000 3.523444e+001 5.392080e+001 0.000000e+000 0.000000e+000 0.000000e+000 0.000000e+000 0.000000e+000 0.000000e+000 0.000000e+000 0.000000e+000 0.000000e+000 2.776806e+001 2.375106e+000 3.280840e+003 0.000000e+000 0.000000e+000 0.000000e+000 0.000000e+000 0.000000e+000 0.000000e+000 0.000000e+000 0.000000e+000 0.000000e+000 </missileParameters>
    <launchSiteName>Iranian Space Vehicle Launch Site </launchSiteName>
    <launchSiteCoords>5.392080e+001 3.523444e+001 1.000000e+003 </launchSiteCoords>
    <missileAuthors> Geoffrey Forden </missileAuthors>
    <article> </article>
    <journal> </journal>
    <description> The parameters for this missile were derived from graphical analysis using data from “Flight Performance Handbook for Powered Flight Operations”, J. Federick White, editor, (1962). It was based on the assumption that Iran would launch a two stage missile (what the US MDA supposes) carrying a 750 kg warhead (just slightly over the 500 kg nuclear device Iran is rumored to have bought from the A.Q. Khan network) a distance of 10,000. The first stage thrust was adjusted in units of Nodong engines to reach the planned point. </description>

    Cut and paste it into a text file and use the program to read it in and run.

  2. Ryan Crierie (History)

    I find your conclusion that an Iranian ICBM is not a logical consequence of developing a SLV completely baffling.

    If you can place a reasonably large payload into orbit around the earth, then it’s only a matter of systems integration work to downscale that capability into an ICBM.

  3. Geoff Forden (History)

    I absolutely agree with you except for your assertion that I said Iran could build an SLV big enough, something I never said.

  4. Ryan Crierie (History)

    I never put words into your mouth.

    I merely pointed out that there is no bifurcation between military rocketry and civilian rocketry, and that as Iran develops ever more capable space launch vehicles, it’s ICBM capabilities improve as well; and vice versa.

    Iran already has a theoretical ICBM capability in it’s current Safir SLV, which coincidentally is in the same dimensional and weight class as the cancelled Midgetman (compare their dimensions), being able to put about 120~ kg or so onto CONUS targets, at some point, the improvements to the Safir and the increasing minaturization of Iranian devices will mean that they gain an operational weapons system roughly the same dimensions as our Midgetman.

    Secondly, the Iranians have openly admitted they are working on a manned space program to put someone into orbit in the next 10-15 or so years. If we assume that their spacecraft weighs as much as the first Mercury capsules, they will need to develop a launch vehicle capable of putting 2,000~ kg into low earth orbit. That’s well within ICBM class.

  5. Hairs (History)


    Thank you very much for your posts – I found them (and also Joschka’s obviously knowledgeable comments) very interesting. The whole series is much appreciated.

    I have to confess that I’ll need to read the posts several times over, and perhaps do bit of note taking, to organise in my own mind who thinks what about which system. Perhaps the Iranians’ (annoying to me) habit of changing the names of what seem to be identical rockets is also just a ploy to confuse people like me! 🙂

    If I may, I’d like to make a suggestion for a future post: my own experience (admittedly not in rocketry) is that technological progress tends to advance at pretty much the same rate regardless of the era. Whether it’s deep sea offshore drilling, or developing advanced gas turbines, each country or company takes a similar number of years to progress. I guess the laggards, who tend to be smaller, can compensate their lack of industrial capacity by using more up-to-date technology and learning from the open literature. Which means the fundamental rate of advance is probably determined by the personal experience of individual engineers and scientists. Your story about the Scud timer shutting the engine down too early had a horribly familiar ring to it, and I can think of dozens of my own experiences that are very similar!

    Therefore, how about a timeline comparing the years it took the major powers to develop critical stages in rocketry? How long did it take the Americans / Soviets / Chinese / Indians / Japanese etc to go from vanes to vernier engines to gimballed main engines? What about advances in propellants, or guidance technology, or multi-stage developments? As an outsider I would guess that there are maybe half a dozen key technologies that have to be mastered to go from each rocket generation to the next, and I’d be interested to see how the Iranians stack up against history.

    If such an exercise were possible, and obviously it can only be done by someone with a good knowledge of rocketry, I think it would probably be just as illuminating as any “formal” intelligence estimate. I very much hope you might have time one day to try this because, to paraphrase Churchill, “The farther we look back, the farther we can see forward”.

    Many thanks.

  6. Tal Inbar

    I think that iran might develope a solid fueled SLV, when it will mastered the casting of large diameter solid fouled rocket motors. The Safir slv has only marginal space lift capability. Even the segil prduces more thrust at lift off.

  7. Jochen Schischka (History)

    To Tal Inbar:

    I’d consider solid-boosters as not the best option for a space-launch-vehicle (high vibration- and noise-levels! high acceleration near burnout!) – but it surely is possible if you don’t mind strapping something with the average density of liquid hydrogen (the satellite) directly on top of your (much bigger and a lot less smoothly burning than a liquid-fueled) combustion chamber…

  8. Badtux (History)

    Ryan, 120kg is not much payload and Iran does not and will not have in the foreseeable future the ability to design any 120kg payload which would be thermonuclear in nature. Both uranium and plutonium are very heavy metals and the available bomb designs (the ones that would not require the Iranians to do significant development work beyond what the U.S. did in 1941-1945) require a payload of around 750kg minimum. It was not until 1962 after almost twenty years of nuclear device development work that the US designed a thermonuclear device that would fit into a 120kg payload (the “Little John”), and the 5Kt yield isn’t exactly earth-shattering.

    Reality is that to get a good warhead that will do something useful (like, well, destroy a city, rather than just a few city blocks), you’ll need to be able to boost at least the 750kg of the W-49 warhead used on the Atlas I missile into orbit. That is the calculation that Geoffery is doing, and as he shows, Iran will have to develop significant technology in order to do so — and it’s pretty darn unlikely they’ll do this without taking at least the twelve years that the U.S. took to do it as the U.S. progressed from captured V-2 missiles to the Atlas missile. A 120kg payload is fine for a surveillance satellite — militarily significant in and of itself — but simply will not work for any other military payload worth delivering at this time.

  9. Jochen Schischka (History)

    Good point, Badtux!

    That said, the U.S. had a much broader industrial and financial base to begin with AND the direct help of most of the german engineers that designed the A4/V-2! (Maybe the iranian missile-program also relies on external help? They should have enough oil-revenue at their disposal to pay for this…)

    And let’s not forget another very important issue: accuracy!

    Even if you possess a nuclear warhead (the triconic “baby-bottle”-RV with approximately 350l volume and 500-800kg weight would be inapplicable on an ICBM due to the much higher speeds and thus heat-loads involved – a blunt nose, other materials and an additional heat-shield would be required), you’d also need appropriate guidance systems and reentry-techniques to have an actual chance of destroying or damaging your intended target.

    As i understand, the Iranians currently use Horizont-Vertikant-guidance-systems similar to that of the Scud on their missiles. Scud-B has a CEP of about 1km over a range of 300km (under good circumstances – the Libyans didn’t even hit Lampedusa with their Scud-B-shots back in ’86, and that island is not exactly THAT small) – thus an 1800km-range would result in a CEP of around 6km and an ICBM with 10000+km range would have a CEP of over 33km! Even if you take a separable (but, as demonstrated on the Ghadr-1 and Sejil, neither post-boosted nor aligned nor spin-stabilized) warhead into account, you’d still end up with an approximated CEP of 11km or more for a hypothetical ICBM (this was the reason why early ICBMs tended to carry huge multi-megaton-nukes) – and maximum deviation (important if you can’t afford to launch a saturating barrage -> “the first shot counts”) would be again around three times that number!

    I’d say that aiming at New York and then killing only fishes in international waters is a premium way to become the world’s greatest laughing stock…

    On the other hand, the Iranians seem to follow the much more complicated (than plutonium) uranium-path to fissionable material – obviously in combination with a rather ambitious compact-implosion-type-approach. Complexity plus complexity results in what? And we’re still not talking about fusion-boosted or even multi-staged (thermo-)nuclear devices with an anywhere nearly adequate area of effect to compensate for the expectably low accuracy.

    And then there are still the difficulties of transporting a nuclear payload with a missile, especially demanding in combination with solid-fueled carriers…

    So in essence, until somebody massively helps them (aka SELLS them prefabricated missiles with functional warheads – or at least, the most complicated components and technologies), the Iran (and/or North Korea) will still have a loooong way to go…

  10. Hairs (History)

    I don’t think we should so readily assume that Iran, or anybody else for that matter, has to achieve accurate delivery of a nuclear weapon with a missle. After all, if an attacker really wants to cripple New York, or Rotterdam, or the Ras Laffan industrial complex they’d undoubtedly be able to load the weapon on a suitable container ship or tanker and just sail it there. For sure, these ports have security features, but I can’t imagine it is more difficult to get a ship unsuspected into a particular port than it is to launch and accurately land an ICBM.

    Thus if accuracy is limited, a nuclear tipped missle would be far more useful as a broad strike weapon for attacking the enemy’s infrastructure. A reasonably sized nuclear explosion about 400 – 600 km above Kansas would expose the entire continental to a large electromagnetic pulse, wiping out the functionality of non-military radars, satellite communications, landline telephones, radio communications, cellphones, wi-fi, satnav, and dozens of other things I can’t even think of. Additionally, the induced currents in very long conductors e.g. power cables, may well cause breakers to open, resulting in a cascade of isolations and power-plant trips to the point where the grid collapses (note: solar activity did this to Canada in the 1970’s, and an atmospheric EMP’s field strength is several orders of magnitude stronger than that from solar activity). Military equipment is (presumably) hardened against this sort of attack, but it’s probably safe to assume that even some of that will be affected. The physical damage may be comparatively light, and some power grids and mobile phones might be up and running again within hours or days, but the economic damage and infrastructural shock would be immense; we have only to look at New York or New Orleans in recent years to see how fragile a integrated, 24/7, “just in time” society is.

    In such a circumstance, would the USA – or any nation with the capability – launch an all-out counter-strike to annihilate the initiating country? I don’t know, and fervently hope we never find out. But as the Serbian bombing campaign and second Gulf War showed, attacks on infrastruture are every bit as effective (maybe even more effective?) than simple killing of soldiers and civilians as a way of bringing the target country to its knees.

    Consequently I believe that the accuracy of an ICBM is only a secondary consideration; if you wish to land your warhead directly on the top of a hardened silo a continent away then accuracy is nice to have as a first strike capability, but if you want to damage your opponent’s economy and infrastructure then you’ve only got to be good to within a hundred (vertical) kilometres or so.

  11. Jochen Schischka (History)


    EMP sure is a nice feature (although i think you overestimate the range – will the field strength not fade away with 1/r²?), but let’s not forget the fact that the REAL threat of a nuclear explosion is direct blast-, heat- and radiation-damage!

    If i launch a (very expensive) nuclear-tipped missile (especially at a country with missile-tracking-technology and thermo-nuclear counter-strike capability), then i don’t want to annoy some people by depriving them of their technological toys (although you might not believe this now, but life without an electrified can-opener or 24h-TV-coverage or mobile phone IS possible…) – i’d want to KILL as many people (not fishes!) as possible and see my enemy’s cities burn to cinder!

    And i certainly have to be completely insane to do this as a first-strike without the ability to kill off the opponent’s counter-strike-capability.

    It’s not a particularly good idea to only pinch a sleeping giant (exactly what i understand “damaging the opponent’s economy and infrastructure” would be – as you correctly noted yourself, some if not most of these effects would only be temporary in nature and military capability wouldn’t be considerably affected at all) – either you break his neck with the first blow or the only thing you’ve achieved is making that said giant very, VERY angry at you!

    If my estimations of a (still hypothetical) iranian first-generation nuclear weapon are right (unboosted uranium-implosion-type with ~20kt), the lethality-radius of such a device would only be about 1200m, so a CEP of 11000m is about an order of magnitude too inaccurate! Let’s make this 50kt with fusion-boosting, so we get a lethality-radius of approximately 1500m – still insufficient! Either you reduce the CEP (or better max deviation) to a reasonable number or boost the explosive force of your warhead up to about 20+Mt to have an actual soft-target kill capacity with your ICBM (and much, much more than that for hard-targets). Otherwise you get a mere terror- and/or propaganda-weapon that is preferably used as a bargaining token for “disarmament negotiations”. This whole issue can be reduced to one single question:

    Do you really believe that fear (and/or discomfort for the civil population) alone can win a war?

    (Did the german V-Weapons-bombardment of London spread fear? Of course, but did it win the war? What did Saddam’s Al-Hussain-shots at Israel or the torching of the kuwaiti oil-fields accomplish? To what extent did the bio-weapons-program help imperial Japan in winning WW-II?)

  12. Hairs (History)

    As for other effects, I’ve got muchh less knowledge to bring to the table. We can probably assume that a lot of non-hardened circuitry is going to be damaged by voltage spikes, so there’s a good chance of many automobiles, trucks, buses, emergency vehicles, etc not functioning if they are within line of sight of the explosion. How many? I haven’t a clue, but maybe enough to seriously disrupt food distribution, police, fire fighters and so forth. There are also the aircraft already in the air when the bang goes off. Again, I don’t know how many people are in the air at any one time between, say Ohio and Chicago, or between New York and Washington, but I don’t believe civil aircraft are hardened against microwave penetration (lightning strikes yes, but I think not microwaves) which means a great deal of their control circuitry is susceptible. In any case, any ground radar that has survived the pulse will be looking at an ionised atmosphere, and air-ground communications will be dead except for line of sight (assuming the trasnsmission and receiving circuitry hasn’t been damaged by the pulse-induced voltage spikes). I think there’s a good chance quite a few aircraft will fall out of the air. Death toll… who knows?

    I don’t deny the thermal and shock effects of a nuclear weapon, but I can’t agree that they are the only threat from such a weapon. (It’s worth recalling here that so-called neutron bombs are deliberately designed to minimise physical damage, while maximising deaths).

    Also, I disagree with your comment that you’d “…have to be completely insane to do this as a first-strike without the ability to kill off the opponent’s counter-strike-capability.” I don’t think any nation, not even the USA itself, believes that it could kill off its likely-opponent’s counter-strike-capability. Yet, USA, Russia and China still point weapons at each other.

    If Iran were in a situation where it could launch a weapon and have, say, a 95% chance of achieving the effects I’m trying to describe, or only a 20% chance of blowing a city away (with the remaining 80% wasted on the fish), which would it choose? I suspect the former, because it is launching in the knowledge that it has either been pre-emptively attacked, or that it will suffer devastating consequnces whatever it does (because it can never in the near future hope to decapitate the US’s retaliatory capability).

    Regarding your question: Yes, I do believe that fear or “discomfort” (as you put it) on its own is sufficient to win a war. It happened in Serbia not so long ago, when a sustained bombing campaign intended to reduce casualties but maximise infra-structural damage, caused the Serbs to sue for a halt after several months.

    Similarly, the outcome of the Cuban missile crisis was determined largely by fear; had that fear of nuclear warfare not existed there is every chance that the Americans would have invaded Cuba, or taken other miltary action. Instead, in return for quietly removing some of its own missiles from Turkey, America got the Soviet missiles removed from Cuba. Since that was the whole aim of the US’ confrontation it’s hard to see it as anything but a “win”.

  13. Hairs (History)

    Apologies to all – I tried to post a long response in three parts. The bit above (03 Dec, 09:37) was actually part 2.

    Part 1 was:

    Yes, field strength would drop by 1/r2, but the ionisation of the atmosphere, which is responsible for blacking out anything but line of sight e.m. communcations, is caused by the weapon’s X-rays; thus the atmosphere is ionised out to the visible horizon, which roughly encompasses the continental US as seen from about 500 km.

    As for the other effects, if anything I think I’m probably being a little conservative. For example, regarding the induced currents in power lines, these are greater the longer the conductor is (it’s a major problem for any grid designer, and the reason we have so many protections across the grid) so the US electricity grid would certainly be collapsed by a significant EMP event. In the process there will be plenty of surges causing physical damage to some components (the grid’s microwave communcations and SCADAs would also be burned out – so even if the grid were physically able to recover it would be impossible to start because there’d be no measurement or control signals) and many of the nuclear power stations – the backbone of the US in some regions – will be poisoned out, so they can’t restart anyway.

    A great number of power stations in remote areas are controlled remotely (at one time I used to start and run-up 150 MW gas turbine peak plants from over 100km away using my laptop and cellphone) so the loss of landline and wireless communications would make these unavailable. In any case, any functioning communications would be swamped by a panicked population (just like London on 7th July).

    I’ve been involved in (though thankfully not caused!) more than 10 grid collapses and regional collapses, all in countries – obviously! – where it a frequent occurrence. These places are much less integrated than the US, and there are many, many back-up generators and alternative plans precisely because the grid fails so often. At a guess I’d think the grid would be out for 1 or 2 days completely, and locally for up to a few weeks. It would certainly be quite an effect if the weapon wasn’t aimed at the entire US but, say, exploded 150km above the north-eastern states. Do this in the winter, and you could probably manage a few hundred to a few thousand deaths (we can refer to the Canadian ice-storm experience for what happnes when you lose the grid for a few days at a time in a harsh winter).

  14. Hairs (History)

    Part 3 was:

    Then there is the fear of confrontation that prevents the USA / South Korea marching into North Korea in the way that was done with Iraq. The difference, in my opinion, is that North Korea is suspected to have nuclear weapons, whereas Iraq was suspected (wrongly, it turns out) of only being in an advanced state of developing them.

    If fear doesn’t win wars, why did the Japanese surrender after two nuclear weapons were dropped on them, when prviously they had vowed to fight Okinawa-like to the bitter, bloody end?

    The list is long, and if we start to look at “terrorism” (however we define it) there is no shortage of governments that have entered talks with the “terrorists” because of the continuing attrition of attacks. If that isn’t a manifestation of fear and discomfort, then I don’t know what is. The unpalatable truth is that terrorism occurs because terrorism works. To misquote Al Capone: “I find a kind word and a gun gets me more than a kind word alone”.

    Iran could not hope to take on the US in a full-blown nuclear war. So if it did develop nuclear weapons, what would they be for? Answer: terrorism (just like the US, UK, France, etc etc – only we prefer to call it “deterrance”).

    I still contend that if they had to choose between a low chance of killing people with blast and heat, or a high chance of damaging infrastructure and economy (and killing a few thousand into the bargain) then they’d go for the second option. If that seems insignificant I can only say that 9/11 was small in comparison to the effects of an atmospheric nuclear burst, yet look what it did in terms of deaths, economic damage and fear.

    EMP is not as spectacular as blast, and probably won’t kill as many people, but neither is it a negligible event – especially when it may be the biggest credible threat a country is able to make.

  15. Jochen Schischka (History)


    I think we have to clarify one thing: i was talking (or writing) about a militarily useful, working weapon (which MUST, per definition, be realistically capable of destroying a specified, mostly military-natured target) and a “hot” war (involving actual combat). In this context, terror-weapons not capable of doing aimed damage (although some mischief and suffering might be created) are more joke articles than anything else and anybody using them against better knowledge will loose his credibility (see V-2 at London…or Al-Hussain at Tel-Aviv…i think i mentioned these examples already…).

    You assume a symbolical (aka NOT realistically capable of destroying a specified target, especially considering the opponent’s military capability) weapon with primarily political value and a “cold” war (which is, as i understand, a sort of conflict where both sides are so frightened of each other that nobody wants to start real hostilities). This is where your Cuba-example fits in: the Kennedy-administration wanted to avoid a real war at (almost) all cost – and the missiles on both sides were then used as a “bargaining token” in “disarmament negotiations” (EXACTLY as i wrote…except that these missiles really worked…).

    I do not deny the possibly even immense political value of such an inaccurate, not really working weapon, but in a real shooting-war, it is like threatening an assault-rifle-armed precision-shooter with a sawed-off shotgun over a distance of 200m – bad idea, if you ask me.

    Unfortunately, western societies tend to hysteria; Anything causing discomfort or even only fear is rampantly overinterpreted with partially devastating consequences for the civil population. Let’s take a closer look at the Al-Hussain-Tel-Aviv-example: In essence, Saddam pretended to be able to hit Tel-Aviv (have you ever seen a map of the impacts? Some landed in the mediterranean sea while others struck the West Bank…and all this with only ~300kg explosives per warhead), while the Israelis pretended to be able to shoot the incoming missiles down (creating considerably more debris raining down on their own city in the process). But the (unsubstantiated – the iraqi C- and B-weapons-warheads for the Al-Hussain would never have worked anyway as far as i can tell) fear of chemical weapons created more deaths from heart-attacks and misuse of gas-masks than the actual Al-Hussain-(and Patriot PAC-2)-warheads!

    Of course an EMP-attack could cause suffering and even deaths (e.g. airliners crashing, car-accidents caused by failing traffic lights, people suffocating in stuck elevator cabins etc.). But compare this to the total annihilation caused by Little Boy and Fat Man! Who did win in the end – the one with the miserable life circumstances for his population or the completely annihilated one with the DEAD population?

    And the Japanese clearly surrendered because the U.S. started to eradicate their cities one by one – NOT because of the trade embargo or the effect on their economy (BTW has anybody ever heard of terrible, completely disrupting EMP-effects in Hiroshima or Nagasaki? Of course, they were not that extremely computerized back then, but have there ever been recordings of noteworthy effects at all? I’d consider especially Fat Man as a very appropriate model for an iranian first-generation weapon in this context).

    ACTUAL DESTRUCTION, not hypothetical statistical possibility or symbolic actions…

    Considering the fact that “USA, Russia and China still point weapons at each other”:

    This is EXACTLY what MAD (Mutually Assured Destruction) means! And we haven’t had a nuclear war in the last 60 years, because:

    a) the U.S. is not very bellicose/aggressive (otherwise, the Kremlin would have been nuked in 1946 and the Russians would talk american-english nowadays…);

    and b) because everybody is afraid of a couterstrike on his own country! This is EXACTLY the point i wanted to make: NOBODY IS (yet) INSANE ENOUGH TO RISK A FIRST-STRIKE IF HE CAN NOT ELIMINATE THE OPPONENT’S COUNTER-STRIKE-CAPABILITY!

    BTW, you may be right with your assumptions considering the diameter of effect of EMP (isn’t it the gamma-, not the X-rays? Although that difference is only academical in this context) under two conditions:

    a) It is a (big?) nuclear weapon optimized for NEMP (something i simply don’t believe the Iranians/North Koreans could possibly achieve on short notice without massive help), and

    b) the detonation is taking place at a height of over 30km.

    Otherwise (detonation at blast-optimized height which should be around 600-800m, ~20kt, pure fission) NEMP would only affect an area with a radius of about 3-6km (this is only a rough estimate – has anybody better and preferably verifiable data on NEMP under these conditions?).

  16. Hairs (History)


    It’s very illuminating to debate with you, but I think we must agree to disagree over whether an inaccurate nuclear weapon has any “military” value (beyond the terror / fear / political value that – I think – we agree on).

    Regarding EMP effects specifically, if they were negligible in military importance I don’t think we would see large budgets spent on (A) Hardening military equipment against just this sort of attack (B) Development of specific EMP weapons using flux compression or (probably in the medium future) free-electron lasers.

    Regarding Hiroshima / Nagasaki, I suspect we saw few EMP effects for two main reasons:

    1) There wasn’t a great deal to affect at the time.
    2) More importantly, the detonations were much too low to generate sustained plasma conditions – certainly these weapons were detonated much lower than the aircraft that carried them, and at the air densities that can support aircraft the atmosphere is an order of magnitude too dense to sustain the free Compton electrons needed for the effect. That’s why detonation has to occur above 50 – 100 km, otherwise the electrons quickly rebind to the available ions and all you get is heat.

    Your analogy of the shotgun versus an assault rifle illustrates very well what I was trying to say in my earlier posts; undoubtedly any nation would prefer to have an assualt rifle too, but if you don’t have one are you going to use the shotgun in the best way you can, or are you just going to do nothing because you don’t have a weapon as good as the other guy? I suspect that if it came to it, Iran would use the shotgun in the best way it could. The fact that the shotgun is vastly inferior to the assualt rifle is besides the point, if it’s all you’ve got then you use it. And if you think there’s a good chance you’ll miss (the guaranteed kill of) a headshot then better to aim for the bigger target of the body and do what wounding you can. For sure in this conflict the shotgun’s worse than the rifle, but the shotgun’s still better than nothing. And that is how I view inacurate nuclear weapons: they might be pretty useless compared to accurate nuclear weapons, but if they’re all you’ve got then they’re also the best you’ve got!

    I hope you won’t take offence if I stop contributing to this thread for a while because I’ll be away for a few days and I wouldn’t like you to think that I am ignoring any replies you send. I enjoy reading your posts even if, as mentioned, we disagree on this one.


    P.S. As you point out, X-rays and gamma rays are different only in their energies. I use “X-rays” because the gammas soon lose energy in Compton scattering and thus quickly become X-rays. For this reason, X-rays soon dominate by number.