I think I'd argue the opposite. I wouldn't compare hackers to nuclear missiles, but defending against hackers doesn't seem to be realistically possible. Consider the state of the security world now, how many piles of money already get thrown at security, and how vulnerable everything still is. With that in mind, I find it hard to believe that even in the fantasy world of all of the "good guy" nations, whoever you think those are, working with vendors to fix every flaw they find instead of holding them for later exploitation against selected targets, that the security landscape would be meaningfully different. Somebody would still find and hold zerodays and use them in attacks. Whoever that is would have a huge advantage against whoever didn't.

I suppose in a perfect world, we'd all melt down all of our guns and turn them into wrenches or something instead and all live in harmony. But we don't live in that world. In the real world, if you melt down all of your guns, someone else will keep theirs, and use them to take your stuff, because you can't hurt them anymore. And similarly, if you disclose and patch all of your zerodays, someone else will still have their own, and will use them to hack your stuff and cause you damage, and you'll have no way to fight back, except to break out the guns and start a hot war with them.

We're still learning how things work in the cyber-war realm, but I feel doubtful that it'll ever be possible to have defenses so good that you can rely on the fact that nobody can touch you.