Thread by @james_acton32

China is building more than 100 new ICBM silos--a major discovery by @ArmsControlWonk and @dex_eve and reported by @JobyWarrick.

My working hypothesis (as mentioned in article) is that China will deploy much fewer than 100 new missiles. (1/n)

washingtonpost.com/national-secur…

Essentially, I suspect that China will seek to hide a relatively small number of real ICBMs in a much larger number of silos and dummy ICBMs--a form of "shell game" intended to complicate U.S. efforts to destroy China's nuclear forces. (2/n)

This scheme was originally developed in the Carter administration for the MX missile. The US planned to build 4,600 (not a typo!) shelters to hide 200 ICBMs. Ultimately, the Reagan administration changed plans, largely for reasons of domestic politics. (3/n)

The Chinese system is still under construction so it's difficult to say for sure whether it's another shell game (the final road network should give us a big clue). But there's a few reasons to think it is. (4/n)

First off, the layout of China's new silos is totally different from its silos elsewhere. Compare one of these other silo clusters (left, kindly provided by @dex_eve) to the newly discovered cluster (right).

The hexagonal lattice (thanks undergraduate minerals course!) of the new site would facilitate the rapid shuffling of ICBMs and decoys. (6/n)

Second, the terrain is totally different from China's other silo clusters--much flatter--which would again help with shuffling missiles and decoys (and would forfeit whatever terrain protection mountains provided against ballistic missile attack. (7/n)

Third, and this is key for me, is the spacing between the silos. As you can see from the images, China's other silos are 10s of kms apart. The new silos are about 3 km apart. The Carter admin's plan called for silos 1 mile apart. (8/n)

https://twitter.com/james_acton32/status/1410327201610862596?s=20

In general, you want silos as widely spaced as possible (not least because it increases the difficulty an adversary would face in attacking your silos nearly simultaneously). So the smaller spacing doesn't make much sense, except as part of a shell game. (9/n)

(BTW If you're wondering about dense-pack, the spacing is too big for that and layout all wrong. If you're wondering what dense-pack is, consider yourself lucky.) (10/n)

Finally, I'd also point out that the Pentagon doubts China has enough fissile material to build more than 200 or so additional warheads--which could become an issue depending on how many the DF-41 can carry.

media.defense.gov/2020/Sep/01/20…, p. 87. (11/n)

Anyway, if you want to know more about the US shell game here's the seminal OTA study: ota.fas.org/reports/8116.p…

It contains schematic of the U.S. plan--which is on a different lattice arrangement but otherwise fairly similar to China's layout. (12/n)

As you probably guessed by now, I got a sneak peek of the data from @ArmsControlWonk so want to say thank you to him. And also congratulations to him and @dex_eve on a remarkable discovery. (13/13)