Given the limitations on nuclear research for weapons purposes any information that can be gleaned from these experiments that is 'dual use' is more than welcome with the parties that are currently stymied by various arms control agreements. This is also why you will see a lot of supercomputer capacity near such research, it allows simulation of experiments with high fidelity rather than the experiments themselves. These are all exploitation of loopholes. The biggest value is probably in being able to confirm that the various computer models accurately predict the experimental outcomes. This when confirmed at scale will allow for the computer models to be used for different applications (ie: weapons research) with a higher level of confidence.
Presumably these computer models are mostly useful for creating new designs (since the old designs were proven by real tests). Would such new designs be convincing enough to the adversary to fulfill its role as a strategic deterrence?
When (in XX years?) almost all US nukes are only simulated on computers and not actually tested, the Russians may start wondering if the US aresnal actually works, no? That would be a horrible outcome, since it means the Russians would be taking somewhat greater risks in their decision-making. Wouldn't far outweigh any opertaional or financial benefits the newer designs offer?
I suppose one could argue that if the loss of confidence in strategic weapons matched the actual loss in reliability, it might be a "no op" (although even this is arguable). But if the Russians think the US simulations suck, while the US is actually building really good simulations, the loss of confidence would be greater than the actual loss in reliability. In the extreme case, the nukes work great, but everyone thinks they are scrap metal.
Of course, the same happens in reverse: if the Russians are upgrading their weapons to untested designs, the US may start underestimating the risk.
> the Russians may start wondering if the US aresnal actually works, no?
If anything the last year or so has probably made the reverse happening and the US and its adversaries likely both have very high confidence in that the US arsenal actually works.
Or the US finds that after x many years bombs degrade in unexpected ways, and that while we were able to figure this out and fix it. Then we speculate that the Russians probably haven't fixed theirs in the same way and their bombs aren't good anymore. Which means the risk of a nuclear war just jumps up, since MAD is compromised.
