why most perfect algorithms that recreate a strawberry on the molecular level destroy the planet as well.
Phrased like this, the answer that comes to mind is “Well, this requires at least a few decades’ worth of advances in materials science and nanotechnology and such, plus a lot of expensive equipment that doesn’t exist today, and e.g. if you want this to happen with high probability, you need to be sure that civilization isn’t wrecked by nuclear war or other threats in upcoming decades, so if you come up with a way of taking over the world that has higher certainty than leaving humanity to its own devices, then that becomes the best plan.” Classic instrumental convergence, in other words.
Erm… For preventing nuclear war on the scale of decades… I don’t know what you have in mind for how it would disable all the nukes, but a one-off breaking of all the firing mechanisms isn’t going to work. They could just repair/replace that once they discovered the problem. You could imagine some more drastic thing like blowing up the conventional explosives on the missiles so as to utterly ruin them, but in a way that doesn’t trigger the big chain reaction. But my impression is that, if you have a pile of weapons-grade uranium, then it’s reasonably simple to make a bomb out of it, and since uranium is an element, no conventional explosion can eliminate that from the debris. Maybe you can melt it, mix it with other stuff, and make it super-impure?
But even then, the U.S. and Russia probably have stockpiles of weapons-grade uranium. I suspect they could make nukes out of that within a few months. You would have to ruin all the stockpiles too.
And then there’s the possibility of mining more uranium and enriching it; I feel like this would take a few years at most, possibly much less if one threw a bunch of resources into rushing it. Would you ruin all uranium mines in the world somehow?
No, it seems to me that the only ways to reliably rule out nuclear war involve either using overwhelming physical force to prevent people from using or making nukes (like a drone army watching all the uranium stockpiles), or being able to reliably persuade the governments of all nuclear powers in the world to disarm and never make any new nukes. The power to do either of these things seems tantamount to the power to take over the world.