This is really insightfull, thanks for sharing.
The vulnerability of American infrastructure is not a secret, but exploiting it remains an act of war and contrary to Republican fantasies, few countries in the world want war with the US.
There are also non-state actors to worry about, some of which are already at war with the US.
I'm honestly more woried about losing the grid to a (cyber)sabotage attack than any nuclear incidents, because I think the probability is higher. But I'm really woried about climate change and the whole madness that is climate change denial. We (as in, the world) are losing precious time that we can't get back.