I’m reading Command and Control by Eric Schlosser, and I came across this paragraph (I quote)
… the SIOP [Single Integrated Operational Plan – OP] often demanded that a target be hit by multiple weapons, arriving from different directions, at different times. One high-value target in the Soviet Union would be hit by a Jupiter missile, a Titan missile, an Atlas missile, and hydrogen bombs dropped by three B-52s, simply to guarantee its destruction.
This feels like a bit of an overkill to me. Do we know what this high-value target was?
After a brief search on this sub, according to this comment by /u/restricteddata, (I quote) The ICBM targeting plans have never been declassified to that level of detail. Still, is there at least a tentative list of what the targets could have been?
Following restricteddata’s advice in the said post and perusing the National Security Archives, I could only find an even more cryptic document. Page 6 says that the Damage Criteria were (I quote again)
(1) Ninety percent probability of severe damage to (censored)
(2) Ninety percent probability of severe damage to (censored)
(3) Ninety percent probability of severe damage to 50 percent of industrial floor space (censored)
Sorry, I’m not a historian, I’m just curious about what could have been so important to target on the U.S. side and to protect on the Soviet side that it would have taken six or so thermonuclear weapons to destroy.
Lots of reasons to over-target:
Some kinds of targets require very high blast pressures to destroy/damage
Things that are physically small are easy to miss with early generations of weapons
Weapon systems did not have perfect reliability
Combine those and it's VERY easy, if you want 90% chance of severe damage, to end up with the conclusion that you've got to target six weapons at a given GZ.
Let's use my new MISSILEMAP to illustrate the point. Let's just say, to simplify things, that we want to make sure that anything buried under Red Square is toast. So Red Square has a diameter of about 300 m, and let's say that we need to put 600 psi of blast pressure on it to consider it destroyed (that's a pretty high number, but par for the course with buried bunkers or hardened silos). With Jupiters based in Turkey, the accuracy was pretty low; the result is that any individual weapon, according to (my nifty) SSPK (Single-Shot Probability of Kill) calculator has only a 15% chance of destroying the target. That means that for 90% confidence in target destruction (where "target destruction" means "one of those shots totally encloses that 300 m diameter target with 600 psi of blast pressure") you'd need to target 15 weapons at the target. (The MISSILEMAP settings I used.) (Note that if you drop your reliability of the missile to a mere 99%, the number required for 90% destruction jumps to 20!)
Now this is not necessarily a very accurate use-scenario — we're only using one kind of weapon, and one really not meant to do this particular job (the accuracy is very low), but it illustrates the point. If we change the weapon from a Jupiter to a Titan II, with its much larger payloads and higher accuracy, we get a 59% chance of target destruction, which means we only need 4 missiles to hit that 90% level of confidence.
You can see how this kind of logic (especially if we made our weapons systems less than 100% reliable!) can lead to heavily redundant targeting. Six GZs is not that much under this logic. Moscow itself had hundreds of weapons targeted at it, redundantly. Is this "overkill"? Depends on who you ask — the military planners would say it was just prudent. But at some point you're re-nuking areas that have been nuked over and over again.
As for figuring out which target it might be — I have no clue, but the limiting factor, geographically, will be that Jupiter. It puts a serious constraint on the possibilities with its range and low accuracy.
For further reading, see the wonderfully-titled article by David Allen Rosenberg and W.B. Moore, "'Smoking Radiating Ruin at the End of Two Hours': Documents on American Plans forNuclear War with the Soviet Union, 1954-55," International Security 6, no. 3 (Winter, 1981-1982), 3-38.