The one significant thing I was confused about was why the upper bound survivability for stationary, land-based ICBMs is only 25%. It looks like these estimates are specifically for cases where a rapid second strike (which could theoretically achieve survivability of up to 100%) is not attempted. Do you intend to be taking a position on whether a rapid second strike is likely? It seems like you are using these numbers in some places, e.g. when talking about ‘Countervalue targeting by Russia in the US’ in your third post, when you might be using significantly larger numbers if you thought a rapid second strike was likely. The reason I’m interested in this question is that it seems likely to feed into your planned research into nuclear winter, which I particularly look forward to.
Also, maybe you intend for your adjustment for US missile defence systems to be negating 15% of the lost warheads rather than adding 15% to the total arsenal? The current calculation suggests that missile defences reduce counterforce effectiveness by ~61%, which seems like not your intention given what you’ve said about interceptor success rates and diminishing returns on a counterforce strike. (I think this change would decrease surviving, deployed US warheads by ~163, so possibly has moderately large implications for your later work.)
The one significant thing I was confused about was why the upper bound survivability for stationary, land-based ICBMs is only 25%.
Good catch! I wasn’t considering the fact that a countervalue attack might be ‘launched on warning,’ rather than after a first strike had already destroyed a portion of a country’s nuclear arsenal. I’ve updated the Guesstimate model in the third post to reflect that full-scale countervalue targeting could get a bit deadlier than I originally accounted for, and I’ll make sure my post on nuclear winter takes this into account as well. I don’t have the bandwidth to update all of the figures in the post immediately, but I should be able to do so soon.
Also, maybe you intend for your adjustment for US missile defence systems to be negating 15% of the lost warheads rather than adding 15% to the total arsenal?
Right, again! Thanks for flagging this. Here’s an updated version of my calculations. I now find that somewhere between ~990 and 1,500 US nuclear weapons would survive a counterforce first strike by Russia. I’ll update the post to reflect these changes soon.
Quibbles/queries:
The one significant thing I was confused about was why the upper bound survivability for stationary, land-based ICBMs is only 25%. It looks like these estimates are specifically for cases where a rapid second strike (which could theoretically achieve survivability of up to 100%) is not attempted. Do you intend to be taking a position on whether a rapid second strike is likely? It seems like you are using these numbers in some places, e.g. when talking about ‘Countervalue targeting by Russia in the US’ in your third post, when you might be using significantly larger numbers if you thought a rapid second strike was likely. The reason I’m interested in this question is that it seems likely to feed into your planned research into nuclear winter, which I particularly look forward to.
Also, maybe you intend for your adjustment for US missile defence systems to be negating 15% of the lost warheads rather than adding 15% to the total arsenal? The current calculation suggests that missile defences reduce counterforce effectiveness by ~61%, which seems like not your intention given what you’ve said about interceptor success rates and diminishing returns on a counterforce strike. (I think this change would decrease surviving, deployed US warheads by ~163, so possibly has moderately large implications for your later work.)
Good catch! I wasn’t considering the fact that a countervalue attack might be ‘launched on warning,’ rather than after a first strike had already destroyed a portion of a country’s nuclear arsenal. I’ve updated the Guesstimate model in the third post to reflect that full-scale countervalue targeting could get a bit deadlier than I originally accounted for, and I’ll make sure my post on nuclear winter takes this into account as well. I don’t have the bandwidth to update all of the figures in the post immediately, but I should be able to do so soon.
Right, again! Thanks for flagging this. Here’s an updated version of my calculations. I now find that somewhere between ~990 and 1,500 US nuclear weapons would survive a counterforce first strike by Russia. I’ll update the post to reflect these changes soon.
Neat. Happy to be a little bit helpful!