Let's say the US balkanizes, becomes decentralized and finally stateless. What to do with the nukes that were left over? Who controls them if there's no central power? Obviously, there should just be no nukes, but let's say other countries that are still states have them, so would it be prudent to denuclearize?
And that was a huge mistake. Ukraine has already paid the price for disarming with the loss of key territory to an adjacent nuclear power, and it's allies left it out to dry.