This is a very good read on the state of the art when it comes to submarine-launched missile accuracy, which are presently inertially guided with a stellar update during flight.

https://thebulletin.org/2017/03/how-us-nuclear-force-moderni...

Thanks for the link, very interesting. So CEP is estimated to be around 100m. Better than I thought but I wouldn’t call it hitting a specific house yet.

What do you consider the primary benefit of pinpointing a particular house in nuclear war?

I don’t know if it matters now but at some point certain targets were hardened to near misses of certain sizes but not direct strikes. So the better your accuracy the smaller the weapon (or fewer) you can use to take out those targets.

So you could say the use would be increased certainty your enemies command and control and other bunkers would be destroyed increasing the odds of “winning” whatever happens afterwards.

There is no "winning" in global thermonuclear war... :/

That’s why I said the guidance is only really usable for nuclear weapons. I wasn’t saying the guidance is bad, I was saying it’s not accurate to a few meters.

https://news.ycombinator.com/item?id=43393504

Oh you're right, my bad. I got lost in the conversation and looking into the types of guidance systems and I forgot that was your original point.

While you probably can't target a cigarette butt on the street, you could definitely hit a building. Especially if the ICBM is paired with image recognition (which it has already for star nav) and/or backup positioning mechanisms like cell tower locations or well-known broadcasting tower locations (think television stations).

An ICBM is coming in at hypersonic speeds in the terminal phase, you’re not going to guide it anywhere using cell tower signals. The guidance is done much earlier.

And I would doubt image recognition for ground features would make it that accurate, too. Before reentry, you’re very high and fast and reentry isn’t that predictable to get you accurate enough to hit a house. And during reentry, you’re not going to see anything though plasma. And after reentry, you probably don’t have enough time and control authority to still guide into a specific house.

ICBM guidance is very different from cruise missiles.

> An ICBM is coming in at hypersonic speeds in the terminal phase, you’re not going to guide it anywhere using cell tower signals.

Hypersonic glide ICBMs have been successfully tested by China, and are under development in the US, so it's entirely possible to maneuver, and optionally guide them in the terminal, though perhaps not advisable on a jammable channel, except perhaps as an anti-radiation weapon.

Yeah that would work for drones and slow cruise missiles but not ICBMs.

Quantum navigation is likely to be more precise.

Down to the Planck scale?

well there is this now as well - you don’t need to use the stars when you already have detailed aerial images of the earth - https://www.spectacularai.com/gps-free