Comment by mschuster91 | Hacker News Reader

Comment by mschuster91 | Hacker News Reader

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> US ICBMs been inertially guided for decades. They predate GPS. Once launched, they have no radio inputs.

That's how the original Third Reich V-rockets worked as well, and they were shockingly inaccurate. It didn't matter for the Nazis, as their intention was to spread terror among the British population instead of actually hitting specific military targets, but in a modern war waged under the rules of war, "collateral damage" can actually be a war crime, and even if not, it will provoke significant opposition.

This can at the moment be seen in Ukraine, where Ukraine regularly (and rightfully, IMHO) claims that Russia's strikes violate the rules of war by hitting civilian infrastructure en masse, and where Ukraine's strike capability against Russia is severely impeded by Russian GPS jamming (that also causes serious safety issues for civilian airlines [1]), but also in the current Israel/Palestine war, where Hamas regularly claims that Israeli strikes are too imprecise [2] or unguided [3], while Israel claims it hits hidden weapons caches that subsequently explode and cause a lot of secondary damage [4].

[1] https://www.newsweek.com/finland-estonia-gps-jamming-russia-...

[2] https://www.reuters.com/world/middle-east/israeli-attack-raf...

[3] https://www.lemonde.fr/en/international/article/2024/05/31/i...

[4] https://www.pbs.org/newshour/show/military-experts-discuss-i...

While the V2 made use of a key element of inertial navigation systems (the Pendulous Integrating Gyroscopic Accelerometer [1]), it was apparently only used to cut off the motor when the desired velocity was reached (the other elements of the control system guided it on a trajectory which curved from vertical to 74 degrees as a function of time, with the azimuth determined by the positioning of the rocket on its launch stand prior to firing.) Consequently, the performance of modern inertial navigation cannot be deduced from V2 accuracy (or, rather, the lack thereof.)

[1] https://en.wikipedia.org/wiki/PIGA_accelerometer

ICBMs are gonna have collateral damage

President: ok, hit this military base with 100 soldiers to let them know we’re serious

Million-inhabitants city nearby: burns to the ground due to garbage guidance

President: …dig out the plan for world war 3, I guess.

ICBM is likely to deliver a nuke. Which will probably take out a 20 km radius circular area. It is not going to be used to target a base with 100 soldiers.

It is if the goal is to deter without launching a city roast fest. That’s one possible step to e.g. answer a first limited strike without starting a disastrous exchange. And US nukes can be set to low yield.

If NATO ever has any intention of deterrence through detonating a nuke, it will be done in exactly the way it's been specifically planned and openly explained: France has a specific nuclear policy, one of the only ones, that allows them to use nukes before an adversary does. They have a specific nuclear missile fired by plane that will be used as essentially a giant warning shot.

Nobody would fire a warning shot using an ICBM, because if things are hot enough to require a warning shot, that leaves a whole lot of interpretation up to your adversary who is quite likely to respond with their own ICBMs, before finding out yours were loaded with conventional munitions to make a point.

There are however, shorter range ballistic missiles, Russia has a lot of them (the US mostly gave up mid range ballistic missiles in a nuclear treaty) and has even launched a few with concrete "nuclear warhead simulation masses" at Ukraine.

Or a dozen nukes.

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