Schelling on PALs

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Marginal Revolution points to Thomas Schelling's suggestion that the US should share permissive action link technology link with the Iranians:
It is important for the Iranians to understand — and have access to — technology like we have in the U.S. that disables bombs if they get into the wrong hands. U.S. weapons, for example, have "permissive action links"— a radio signal code that arms weapons but that will also automatically disarm them it if launched at an unauthorized target.

This will be a big dilemma for the U.S. If the Iranians get weapons, will we be willing to share the technology to ensure the security of their use? That is where the debate is heading.

As Steve Bellovin points out in his page presentation on PALs, we offered PAL technology to the Russians (they refused) so I would expect us to offer the Iranians at the point where they get nukes.

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The Iranians would naturally suspect there is a backdoor there to allow the US to disable their weapons. That's probably why the Russians refused.

Another issue tied up with PALs is environmental sensors. The idea is that unless (say) an ICBM warhead experiences an appropriate sequence of events (accelerations, changes in atmospheric pressure, etc.) it will fail to explode when it hits the ground or passes through a certain airburst altitude. Hence, if your missile falls short or something, the warheads won't explode. This is important if (e.g.) you have to fire them over a neutral or friendly country to get at your enemy, and expect a significant malfunction rate.

This sort of thing is also important in the case where your missiles might be intercepted in boost phase by some kind of (let's say) SDI-style ray gun. The idea here is that you zap the missile while it's climbing away from its pad; at this point it is highly visible (because of IR from the engine), it's difficult to deploy decoys, and the thing is fairly vulnerable (because it's still full of fuel which could cook off if illuminated with a suitable LASER, or whatever). If this causes the warheads to fall short, otherwise undamaged, then obviously the people underneath them are going to be keen that they don't go off.

Now let's say you're Iran, and you have a missile you can use to blow up Israel. Such a missile could overfly any of (working from N to S) Turkey, Syria, Iraq, Jordan, Kuwait and Saudi Arabia on its way to its target, depending on launch site. If you equip your warhead with PALs and environmental sensors as above, and decide that the time has come to use the missile, then the owners of the hypothetical ray gun -- presumably the USA -- can decide to shoot it down in complete safety. If not, they risk landing the warhead on one of the above-named countries, so making themselves extremely unpopular.

Now, on the face of it, that's unlikely to influence an American tactical decision to use an anti-missile system (the USA is already pretty unpopular in most of those countries, and it's highly likely that the warhead would land in some bit of desert somewhere and/or not go off, so it would not be rational to leave it to reach its intended target), but it could well influence the decision of some of those intermediate countries in providing bases (for instance, airfields for airborne LASER carriers) or other facilities (RADAR sites etc.) for such a thing.

Scale things up, and consider Iran firing an ICBM against a target on the eastern seaboard of the USA. Flight paths for such missiles pass over countries including Norway, Sweden, the UK, Germany, Romania, Turkey, Iceland and various others, several of which are places where the US has shown interest in deploying bits and pieces of some kind of anti-missile gizmo. The fact that such a gizmo might cause an Iranian nuke to come crashing down on their own territory ought to deter such countries from getting involved in the US's ABM game, and Iran would be foolish to discourage this. (See crude map showing flight paths of missiles from Iran to the US eastern seaboard.)

Let me get this straight: a man attacks me with a knife, I throw him off. He stumbles, and falls upon your child, who dies.

If you get mad at ME you are
1) an idiot
2) a member of the "international community"
3) both
4) both by definition.

Europe is not immune to attack by Iranian missles, and neither are the secular governments in the middle east. Don't think for a minute that Iran has not threated members of each group. The only reason that these nations are not screaming for counter-balistic technology is because we are yet to demonstrate its workability.

I can take the same argument you propose to demonstrate that these "overflight" countries might demand that Iran have PALs installed. Not that such things couldn't be reprogrammed on a dime...

Which is why I oppose giving them this technology: they won't use it the way we want them to use it, at which point it becomes nothing more than potent technology in the hands of fanatics.

Nathan: Did you read Steve Bellovin's discussion of PALs?

This is akin to providing a raving gun nut a set of child locks for his gun, where the locks are a fingerprint reader which he only needs to touch the gun for the lock to fall off (so no delay in arming)

It doesn't actually improve his weapons: It doesn't make them shoot farther or faster or more accurately.

It doesn't actually prevent him from USING his weapons: He can unlock the gun and start shooting, and in the PAL case, with effectively no delay. He can understand how the lock works, and be very comfortable it won't screw up his cone.

But it DOES keep his crazy KID from taking the gun and going on a shooting spree. And since dad may get caught in the resulting crossfire, this is a VERY GOOD THING.

I can take the same argument you propose to demonstrate that these "overflight" countries might demand that Iran have PALs installed. Not that such things couldn't be reprogrammed on a dime...

Correct. However, the incentive for Iran to fit environmental sensors (note, not exactly the same thing as PALs, but AIUI related in American weapons) to their warheads becomes much smaller if they believe that there is a credible threat of a working anti-missile system being built, since the absence of this feature is itself a deterrent to the "overflight countries" from cooperating in an anti-missile programme.

If we have to give them the technology, then by definition, they do not currently have that technology.

So gun collectors are "raving gun nuts"? I find your choice of phrasing, in the current context most distrubing. If the "gun nut" is truly raving, then he is a much bigger threat than his "crazy kid". If he's sane, then he has made it VERY clear to his crazy kid just where the craziness ends.

What's more, the fingerprint lock is FAR from foolproof. It's added complexity to a simple design.

No, I've not changed subjects. The adult in the house really is "raving". He really does have reasons to distrust the technology we might offer. We really cannot trust him to use it as we would like.


And who ensures that these "overflight" countries do not end up on the target list themselves? Once we demonstrate that our technology really works, these countries will be begging (okay, demanding) that we share the technology. We'll mostly provide it, but under one condition: they link to our networks.

The point is the technology, if NOT adopted, provides no benefit.

The technology, IF adopted, provides benefit for BOTH parties: Iran gets safer nukes: They can still be used in anger (reliability IS a big concern on US PALs) but not by accident.

With the proper technology transfer, Iran only needs to trust the technology, not what the US did with the technology.

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