I think you have to zoom out and aggregate quite a bit for this thesis, and ignore the fact that it’s only been a few generations of humans who legitimately had the option to destroy civilization. Ignore the fact that “offense” and “defense” in most cases are labels of intent, not of action or capability (which means they’re often symmetric because they’re actually the same capability). But notice that there’s a LOT of local variation in the equilibra you mention, and as new technology appears, it does not appear evenly—it takes time to spread and even out again.
I think you have to zoom out and aggregate quite a bit for this thesis, and ignore the fact that it’s only been a few generations of humans who legitimately had the option to destroy civilization. Ignore the fact that “offense” and “defense” in most cases are labels of intent, not of action or capability (which means they’re often symmetric because they’re actually the same capability). But notice that there’s a LOT of local variation in the equilibra you mention, and as new technology appears, it does not appear evenly—it takes time to spread and even out again.