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Comment by derefr | Hacker News Reader

On a tangent: it occurred to me recently that we also don't see much use of ICBMs with non-nuclear payloads, despite these being a fairly-obvious "dominant strategy" for warfare — and one that isn't banned by any global treaties.

I'm guessing the problem with these is that, in practice, a country can't use any weapons system that could potentially be used to "safely" deliver a nuclear payload (i.e. to deliver one far-enough away that the attacking country would not, itself, be affected by the fallout) without other countries' anti-nuke defenses activating. After all, you could always say you're shooting ICBMs full of regular explosive payloads, but then slip a nuke in. There is no honor in realpolitik.

So, because of this game-theoretic equilibrium, any use of the stratosphere for ballistic weapons delivery is effectively forbidden — even though nobody's explicitly asking for it to be.

It's interesting to consider how much scarier war could be right now, if we hadn't invented nuclear weapons... random missiles just dropping down from the sky for precision strikes, in countries whose borders have never even been penetrated.

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> despite these being a fairly-obvious "dominant strategy" for warfare

I don't think these are quite as viable as you think. ICBMs are expensive. Probably tens of millions of dollars each, for a single-use item. Cruise missiles cost $1-$2 million to deliver the same payload and have a better chance of surprising the enemy.

ICBMs have longer range, but how often do you need to strike targets more than 1000km past the front line? They're inherently strategic weapons.

> ICBMs are expensive. Probably tens of millions of dollars each

For sub-launched ICBMs (like the UK's nuclear deterrent) you also need to factor in the through-life costs of the launcher platform, and the fact that once it starts launching, it has given itself away. We only have four subs, not all of which are on patrol, so it would be barking to compromise these to deliver a conventional payload.

Which country is "we"? The US has 14 Ohio class SSBNs in service until at least 2029

Probably the UK.

https://www.royalnavy.mod.uk/news-and-latest-activity/operat...

Yes, the UK (I should have made this more explicit).

The UK's current deterrent force is currently expected to be replaced by the successor Dreadnought class [0] in the 2030s. They are currently projected to cost £31 billion (likely an underestimate) for four subs, each of which can carry 8 missiles max. Again, these are a horribly expensive way to deliver conventional explosives when we have cruise missiles instead.

[0] https://en.wikipedia.org/wiki/Dreadnought-class_submarine

Submarine launched ICBMs probably wouldn't be valuable without nuclear weapons though: they're valuable because they're a guaranteed second-strike capability to a nuclear first strike - you might plausibly get the land and air launchers, but there's no way to be sure you got all the subs and you only have to miss 1 (i.e. no country would survive losing 28 major cities).

Without nuclear weapons, they're kind of pointless - you don't inflict enough damage to warrant the expense. But the first strike is also so much more survivable.

> ICBMs have longer range, but how often do you need to strike targets more than 1000km past the front line?

Don't you need to also consider the vast expense countries (okay, mostly just the United States) spend to essentially extend their "front line" well beyond their own borders?

Well the first year of the Iraq War cost the US $54 billion, according to congress's budget[0]. This doesn't include the total cost of the supporting infrastructure need to be able to deploy troops in Iraq quickly, but we can estimate that using the increase in defence budget from 2002-3, or $94 billion ($132B in 2020)[1].

According to Wikipedia, Minuteman III ICBMs have a 2020 unit cost of $20 million[2], so for the cost of an Iraq invasion, the US could have fired about 6600 missiles. Considering the invasion toppled the Iraqi government, it's pretty unlikely that firing 6600 missiles with conventional payloads would have been anywhere near as effective.

[0]: https://en.wikipedia.org/wiki/Financial_cost_of_the_Iraq_War...

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

[2]: https://en.wikipedia.org/wiki/LGM-30_Minuteman#Counterforce

The comparison we're making is whether precision attacks, presumably on roughly building-sized targets, would be cheaper to do from long range via ICBMs (with conventional warheads), or via much cheaper but shorter-range missiles. My guess is that neither ICBMs nor shorter-range missiles could have accomplished what the U.S. military accomplished in Iraq. Presumably missiles alone were responsible for a small portion of that $54 billion.

If I can trust https://en.wikipedia.org/wiki/LGM-30_Minuteman a Minuteman III (which is the current ICBM design used by the US) will land within 800ft (240m) of its intended target 50% of the time. And outside that circle the other 50%.

In other words, you can't really target a "building-size" target with these (with maybe exceptions like the Pentagon).

For nuclear payloads, a few hundred meters of error is much less of an issue, of course.

In the first Iraq war, "surgical strike" was euphemism for undiscriminate carpet bombing. Was the second Iraq war any different ?

Even cruise missiles are horribly expensive for conventional munitions payloads. Cruise missiles were developed to deliver nukes.

An unguided 1000kg "dumb" bomb costs $2,000. A "smart bomb" costs $20,000 to $100,000. A cruise missile costs $1mil to $2mil.

In the scope of any protracted real war, sending out lots of cruise missiles is horribly inefficient. Much much cheaper to send out a few planes to drop 100's of tons of dumb or smart bombs. IOW, you can deliver 10x to 100x more boom if you just use planes and bombs. 1000x more if you use long range artillery. But then, the pilots or soldiers are at risk-- and that is a political calculation.

about cruise missiles, wasn't there one of those DARPA contests to see if a guy in the garage could produce a cruise missile? IIRC it got quite scary and was cancelled or something. Being in the drone and high power rocketry hobby i have absolutely no doubt there's enough knowledge and electronics availability for a guy in their garage to come up with something that delivers 50lbs to a precise gps coordinate a few hundred miles away for less than $10k. Once you do that, it's easy to scale up to 500lbs

I'm skeptical you could hit that sort of range for anywhere near $10K. Forget the electronics, you need an engine powerful enough to lift a few hundred pounds for that distance. Unless you want it detected immediately by early warning radar you need it to fly at a low altitude, like a hundred feet or less. Unless you want it to take forever and be susceptible to infantry with small arms it needs to be traveling fast, in the hundreds of miles an hour. That's simply not possible with an electric system with today's technology, and a rocket engine won't provide the endurance or efficiency you need. That leaves a jet engine or pistol engine. Plus, flying at that speed and altitude means you need an effective autopilot system that uses terrain-following radar. You'll also need some nice guidance packages that allow the shooter to set multiple waypoints, so the missile doesn't have to just fly a direct course. And a 50 lb payload of high explosive just isn't that helpful. There aren't a ton of targets where you only need 50lb of explosives to defeat them, that are also going to stay in the same exact GPS position long enough for your missile to travel a few hundred miles. So you'll want a different terminal guidance method, either some sort of radar sensor or infrared.

I don't think you could get an engine capable of getting you hundreds of miles at that speed and altitude, much less the sensors and guidance system.

Gliders though.

So you use a solid rocket booster or maybe make it air-launched and have it glide to the target? So that is definitely a thing, an example I can think of is the US small diameter bomb (https://en.wikipedia.org/wiki/GBU-53/B_StormBreaker ) or the JSOW (https://en.wikipedia.org/wiki/AGM-154_Joint_Standoff_Weapon ). Though those aren't in the "hundreds of miles" that OP originally proposed, they are in the 50-75 mile range. Those also technically aren't cruise missiles, and don't have the primary advantage of a cruise missile: the ability to travel at low altitudes to evade enemy radars and air defenses.

That said, you could probably make a glide bomb for pretty cheap. The two examples I gave above are in the hundreds of thousands, but I bet if you sacrificed some of the accuracy and payload, and you were really optimizing for cost, you could get that into the tens of thousands

A lot of the cost in defense contracts is paying for guaranteed domestic supply in the event of a war. If you buy COTS parts and outsource your machining I see $10k as very achievable, the majority of that being metal and explosives. The electronics are nearly trivial, but some of the IR tracking is embargoed and hard to get outside the US.

Find me an engine capable of going a couple hundred miles an hour for less than $10K though

Hydro-formed "Escopette"-style valveless pulsejet? They run as efficiently as a turbojet (w.r.t. specific fuel consumption), and Mach 0.7 is way beyond your "couple hundred miles an hour".

It will be burnt up by the time it runs out of fuel, though.

For a good one it has to be hydro-formed out of seamless pipe, which is likely hot-stretched (like wire drawing, but using an induction heating coil in place of the die, and independently controlling the feed-rate and the pull-rate) in advance to retain consistent wall thickness in the engine despite being cross-section after hydro-forming. Also probably incremental hydro-forming with grain-structure-fixing re-heating between stages.

The hard part is just that most of the work is in making the hydro-forming dies/tools, not then using them to cheaply produce more engines.

Fascinating, haven't heard of this. Some googling suggested there is some active research in this area, and at least some active use by hobbyists and by the military in target drones. Seems like a promising angle for a cheaper cruise missile, at least on the engine front.

They are loud, though, because they use ~100 Hz wave compression for their combustion, instead of continuous-flow as with a non-pulse jet.

A solid rocket engine. It's not hard. Did you mean missiles or drones?

You're going to have serious troubles implementing a cruise missile with a range in the hundreds of miles with a solid rocket engine. While most cruise missiles use a solid booster to launch the missile and get it up to the proper speed and altitude, you need an engine to sustain flight. You also need a propulsion mechanism that allows you to control thrust, which a solid engine wouldn't. To my knowledge there is no cruise missile in existence that uses just a solid rocket engine. In theory you could get into the hundreds of miles with just a booster if you use it to get up to a significant altitude and glide the rest of the way. But that largely defeats the purpose of a cruise missile: traveling at low altitude to avoid enemy radar.

Of course, you can definitely make a BALLISTIC missile with a couple hundred mile range using a solid rocket engine, and probably for fairly cheap (especially if you don't particularly care about accuracy)

> BALLISTIC missile

Also: Scud missiles are comparable, made outside western cost inflation, and still ~$1M each. So I'm guessing you can't get a ballistic missile anywhere near $10k (at least, not one that isn't more likely to kill its owner).

Yeah, I got confused. Those are harder to reduce cost on. I had this conversation previously about javelins, etc.

Well, unscrupulous sellers find a way even around embargoes...

https://disclose.ngo/en/article/war-in-ukraine-how-france-de...

(An order of magnitude larger helicarrier contract was cancelled eventually.)

V1 was 160 miles, 1800lb warhead? You saying a bunch of nerds in 2022 can't beat 1940's tech to bring the price down a bit?

I think they can bring the price down a bit, but not to $10K, even with a smaller size payload. Also I should mention the V1 was barely accurate enough to target a city the size of London. Not that adding modern GPS guidance would necessarily cost that much, of course.

There was a man in New Zealand trying to make a very low-cost DIY cruise missile as a hobby project [0]. iirc, he was using a pulsejet engine, but ended up getting shut down by some visits from stern-looking government agents.

0: https://www.theguardian.com/world/2003/jun/04/terrorism.davi...

> wasn't there one of those DARPA contests to see if a guy in the garage could produce a cruise missile? IIRC it got quite scary and was cancelled or something.

This sounds similar to the Nth Country Experiment, conducted by the US in the 1960s. The idea was to see if three freshly minted physics PhDs could design a working nuclear weapon using only publicly available information. In less than 3 years, the three succeeded in creating a credible design for an implosion-style bomb.

https://en.wikipedia.org/wiki/Nth_Country_Experiment

In a world without nukes, we would've been all about precision targeted ICBM munitions. In a war they would've been used to hit government centers, military bases, staging and supply areas, oil refineries and wells etc.

It's an infinite range weapon which arrives in 20 minutes to kill a target your spy satellites see. They would be used all the time.

Conventional Prompt Global Strike is intended to provide the ability to deliver a conventional kinetic attack anywhere in the world within an hour. It has been an active area of weapons research for the US for 20 years. As you speculate, misinterpretation of the launch is a concern. [1]

As opensocket points out, there are many shorter range conventional weapons used across borders. The cruise missiles of gulf war 1 or the drones of the post September 11 world.

[1] https://sgp.fas.org/crs/nuke/R41464.pdf

To tie this in with current events this is exactly what makes the no-fly zone idea in Ukraine so dangerous. All of the things you have to do to establish a no-fly zone and take away the enemy's ability to fire into and effect your no-fly zone look the same as a prelude to an invasion or nuclear first strike. This is made worse by the fact that many of the weapons systems you would be using are dual use. Meaning they were designed to deliver conventional or nuclear weapons. It's a massive gamble that the actions won't be misinterpreted or used to justify moving up the escalation ladder.

There are quite a lot of shorter-range conventional systems. In practice you don't need that inter-continental range for most purposes. For some modern examples you have the Chinese DF-21 and the Russian Iskander system. And a lot of those systems are dual-use: capable of delivering both nuclear and conventional payloads. It's not totally clear what that will mean in a conflict between two nuclear powers. What do you do when early warning radar picks up a ballistic missile coming in when you can't tell if it is nuclear or conventional? Plus this isn't a video game, you won't hear some alarm going off after it detonates indicating it was a nuclear explosion. You'll need to send someone to do a damage assessment, and that takes time.

We have satellites which can detect a double flash (characteristic of a nuclear explosion), the US and probably most other nuclear powers with the exception of perhaps North Korea and Pakistan would know instantly of any nuclear detonation above ground.

Not to mention the net of seismographs across the US. Those would tell us within our own borders if a nuclear detonation has occurred within seconds of impact.

We have seismographs and other measurement & signature intelligence collection means all over the world, and there's an elite unit in the US Air Force dedicated to detecting and localizing nuclear detonations no matter where they occur (as well as event attribution, nuclear forensics, intelligence gathering, etc.).

https://www.airforcetimes.com/news/your-air-force/2019/04/21...

https://en.wikipedia.org/wiki/Air_Force_Technical_Applicatio...

> It's interesting to consider how much scarier war could be right now, if we hadn't invented nuclear weapons... random missiles just dropping down from the sky for precision strikes, in countries whose borders have never even been penetrated.

Why are cruise missiles any less scary? They are indeed used in precision strikes across country borders, and can kill you just the same. The existence of nuclear weapons still allows some countries to use cruise missiles, as we see happen almost every year.

I'd consider how much more docile the nation's of the world would have become sans nuke.

If the possibility of an untraceable, space borne, hypersonic weapon was on the table we might have had a better deterrent than nuclear weapons. The lack of fallout and total deniability makes it almost certain they would have been deployed and quite concisely ended a few conflicts at the onset.

It is alarmingly frightening, moreso even, because the impact could be extremely precise- leaving infrastructure intact.

Nah. There's no point in putting hypersonic cruise missiles in space. Too expensive, and not survivable. Those weapons will be launched from air, ground, and surface platforms. Magazine depths will be so limited that they'll only be used for the highest priority targets. They won't be enough to end any major conflict by themselves.

So why are the Chinese doing it?

https://www.heritage.org/asia/commentary/chinas-new-weapon-j...

The Chinese weapon is ground launched, exactly as I stated. Sure you can boost such a weapon up above most of the atmosphere in order to get longer range, but the downside is that higher altitude flight paths make it easier to detect and counter.

AFAIK, there are no publicized counters to partially orbital hypersonic glide weapons in their glide phase due to their maneuverability and speed. Perhaps THAAD - but it may be difficult to ascertain the target when a weapon can glide halfway across the world

Well in theory the RIM-174 (SM-6) has some limited ability to intercept hypersonic glide weapons. Although obviously that's never been tested.

There are counters to hypersonic glide weapons beyond shooting them down. If you can detect it early enough then the target ship can change course and try to evade. The sensors on those missiles have very limited field of view so if it's not receiving a real time target track data link for course correction then it can be possibly be dodged (depending on how many are incoming, weather, and other factors). Even if the target can't evade, a bit of advance warning would at least allow for cueing EW countermeasures.

Nah? You don't put cruise missiles in space. You put mass in space.

I supposed the point would be to hit the highest priority targets and nothing else. Loss of command and logistics has a profound effect on endurance

Putting mass in space as a weapon is just a silly scifi idea disconnected from reality. Even with modern reusable rockets, launch costs are still extremely high, especially if you need enough platforms to hit time sensitive targets. And the platforms wouldn't be survivable. There are cheaper, more effective ways to fulfill the mission.

Not to mention that you get at most as much kinetic energy out as you put in, minus losses to atmospheric drag and what's needed to drop the orbit (you have to burn retrograde to return from orbit).

> Magazine depths will be so limited that they'll only be used for the highest priority targets. They won't be enough to end any major conflict by themselves.

I'm probably being incredibly naive in saying this, but what about "non-wartime" decapitation strikes — where instead of going to war, you just lob some well-timed hypersonic missiles at your enemy's capitol building / parliament / etc. while all key players are inside; presumably not as a way to leave the enemy nation leaderless, but rather to aid an insurgent faction that favors you to take advantage of the chaos to grab power? I.e., why doesn't the CIA bring ICBMs along to their staged coups?

If you do this, the enemy's nuclear-weapons services will look in the playbook under "what to do if someone kills the government", see, "launch everything as a counterattack", and press the button.

A key advantage of a hypersonic weapon is the possibility of first-strikes to disable the enemy's retaliation systems before they have the ability to launch more-traditional retaliatory responses. Only submarines are likely to be mostly-immune to them.

Sure that type of decapitation strike might be attempted on occasion against weaker countries. The US basically tried to take out Saddam Hussein and his inner circle using precision strikes at the beginning of the 2003 Iraq invasion but they mostly missed.

I don't think you'd necessarily have deniability. We have early warning radars and satellite networks now capable of identifying an ICBM missile launch in the boost phase. Even with only ground-based sensor detecting the missile in the midcourse, it is a ballistic missile, which means the missile follows a predictable trajectory. This can be used to fairly precisely determine what it is aiming at, but also could be used to trace the missile back to a launch site.

Well from space, the point of origin is a bit arbitrary. We could just wait for our satellite to reach enemy territory.

Also, ICBMs in their present form would not likely resemble anything deployed in space

> I'd consider how much more docile the nation's of the world would have become sans nuke.

Interesting. I expected that nuklear weapons made us more docile. It's a huge deterrence for big powers to go to war with each other. I think we are seeing this play out in Ukraine right now. If Russia had no nuclear weapons, I'd expect NATO to have intervened much more directly at this point, especially after seeing that Russia seems much weaker than expected.

That is precisely why Putin keeps saber rattling about Russia's nukes. NATO (but mostly the US) would wipe out the Russian forces in Ukraine in a matter of days. Since he's committed so much of Russia's military to the invasion, the west would effectively castrate Russian defenses and likely all manner of hell would break loose in all those oppressed satellite regimes (hello! Chechenia, Georgia, Belarus, etc.)

The normalization of saber-rattling about nukes is one of the most unsettling outcomes of this whole conflict TBH, and hopefully it's going to be addressed in some way down the line. If every non-nuclear power is suddenly vulnerable to conventional attacks by any rouge state with nukes, the ensuing equilibrium is pretty clear and is not good for overall stability.

I don't feel like anything has really changed in regards to nuclear saber rattling, Biden did so last year in regards to US citizens[0] no less.

[0]https://townhall.com/tipsheet/katiepavlich/2021/06/23/in-gun...

Well yes, but that's just Biden missing the point entirely as usual. The military is sworn to defend the Constitution against all enemies foreign and domestic, so if a mass insurgency is ever needed to counter some future totalitarian government, much of the military will be on that same side. What Putin has been saying is a whole lot more serious than that.

I think he more critically missed that using nuclear weapons on yourself is a massive tactical blunder. Just pointing out this isn't anything new.

Nuclear saber rattling has been the norm for a very long time; it's just that after the fall of the Soviet Union there wasn't much need for it. Things have returned to their more traditional state.

Kim Jong Un would like you to hold his soju.

Putin has been doing it since at least 2014 (along with the more conventional though due to nuclear deterrence more ridiculous threat of "visiting Berlin again").

It's just that until last month it was taken as just posturing to remind the West and the Russians that Russia, as a nuclear power, has to be taken seriously.

>If every non-nuclear power is suddenly vulnerable to conventional attacks by any rouge state with nukes

There's nothing sudden about it, this has been the reality for decades now. We here in the US were on the other side of the matter in Iraq and arguably Vietnam. This is an old truth.

Some in the US even argued for using nuclear weapons on Vietnam, out of frustration with the lack of progress with conventional war.

Imagine how that would have gone -- dropping nukes on the Vietnamese in order to "save" them from Communism.

Thankfully saner minds prevailed.

Yup. Henry Kissinger was a big part of that nonsense, along with a whole bunch of equally sinister stuff. The cluster bombings of Vietnam, Cambodia, and Korea were in many ways directly the result of his machinations.

That reminds me . . . I need to watch Dr. Strangelove again.

in the 80s it was not unusual for armed Russian strategic bombers to cross into US airspace above Alaska and then be escorted back out by US interceptors. I agree nuclear saber rattling is unsettling but it can get much worse than what we're seeing now.

/btw, in other discussions i've been too cavalier throwing around the likelihood of nuclear weapon use in Ukraine. I've thought about it much more since those other threads

Didn't one of the old presidents propose that with the Star Wars program? Drop some metal rods from space and it's supposed to pewpew targets with minimal fuss?

Shorter range ballistic missiles have been heavily used in multiple conflicts around the world for many years. The US military has been researching the possibility of using conventionally armed long range ballistic missiles to fulfill the prompt global strike mission. Potential target countries have no anti-nuke defenses. But there is a risk that Russia or China could misinterpret a launch as aimed at them.

in WW2, Germany used V2 missiles for indiscriminate bombing of cities (primarily London). I can imagine it would look like that, but worse - and having gone to a few museums that showed Blitzkrieg London, that was bad enough as it is.

Agreed about the nastiness of V2 attacks.

However, the existence of nuclear weapons today doesn't seem to have prevented indiscriminate bombing (using whatever weapons: dumb bombs, unguided rockets, cruise missiles) of targets (including cities) in several countries in recent years.

blitzkrieg is something else. You're referring to the London Blitz. https://en.wikipedia.org/wiki/The_Blitz was a bombing campaign (airplanes fly over and drop bombs on cities, a very WWII thing to do). V-1 and V-2 sort of came "after" when rocket and guidance tech developed enough that it was practical to target cities using missles from hundreds of miles away (northern france, I think).

Yes you're right, I meant the blitz, and regular bombing did indeed come first. It's been quite a while since I learned about ww2 history!

Interesting tangent I hadn’t considered before. However, China is testing some ballistic anti ship missiles. https://www.navalnews.com/naval-news/2021/11/aircraft-carrie...

To be fair, if these become a reality, they would likely strike targets in the Pacific Ocean and South China Seas, far away from the US, but the potential to spook nuclear nations is still there.

i would imagine delivering a conventional warhead with an ICBM has a very high risk of being mistaken for a nuclear armed ICBM. Also, they're expensive. Putting a JDAM package on an old iron bomb turning it into the most advanced precision guided munition is very cost effective.

https://en.wikipedia.org/wiki/Joint_Direct_Attack_Munition

>game-theoretic equilibrium

Equilibriums change, every major US platform was at one point designed to be nuclear capable, i.e. cruise missiles now liberally launched from planes/bombers/ships that are all nuclear capable. There's no a reason nuclear countries who get attacked by any US platforms should assume any incoming ordinance ISN'T nuclear, down to gravity bombs, except for expectation - knowing US has overwhelming conventional capabilities and would rather use it than nukes.

Same will apply as conventional ICBM matures - we haven't seen much of it because ICBMs have not been sufficiently accurate unless carrying nukes where CEP in meters don't matter. For countries with power projection, it was dramatically cheaper to get closer first and deliver less expensive ordinance. Conventional ICBMs seem effectively forbidden because most actors assume they're too inaccurate for anything but nukes and too expensive for anything but nukes.

But that's changing - there are hints that PRC is pursuing rapid global strike i.e. US prompt global strike, because IMO it's the great equalizer in terms of conventional mutually assured destruction precisely because it isn't banned. A lot of articles being seeded on SCMP about PRC hypersonic developments that spells out meter level CEP ICBMs designed to conventionally attack strategic target of depth, aka Prompt Global Strike.

Ergo (IMO) PRC maintaining no first use nuclear policy while conducting massive nuclear build up to setup credible MAD deterrence. This sets up the game theory of accepting that conventional ICBM attacks on homeland from across the globe is possible and that it's best to wait for confirmation unless one wants to trigger nuclear MAD. Entire reason US / USSR and countries that could moved to Nuke triad or survivable nuke subs was because it bought more time than hair trigger / launch on warning posture.

This makes a lot of sense for PRC who doesn't have the carriers, strategic bombers or basing to hit CONUS (or much outside of 2nd island chain). It makes a lot of sense for any nation with enough resources for a ICBM rocket force but not enough for global force projection (basically everyone). World will be very different place if such capabilities proliferate. Imagine any medium size country with ability to hit stationary targets worldwide - fabs, server farms, power stations, carriers being repaired in a drydock.

Hypersonics are a boogieman imo. You'll get one volley before everyone starts rolling out flak or other anti-warhead defenses, and hypersonics have a gigantic weakness in not being able to maneuver for beans. Once you're going over a mile per sec -> predicting where you'll be to fill it with crap to destroy you isn't that hard.

Who cares if you can blow up one target once? Unless you marshal enough to wipeout enough infrastructure to really cripple your opponent, it won't do you much good anyway; and if you do cripple them, and they're nuclear, congratulations; you just won a nuclear response. You now have bigger problems.

>anti-warhead defenses

ABM unreliable, require multiple interceptors per incoming - exchange favors attackers who can always saturate. Also expensive, interceptors usually cost close or more than what they're designed intercept. And currently for anyone not US, just getting US to divert 100s of billions to homeland ABM defense is a win as it will take resources from other priorities. This is also assuming ABM works against hypersonics, including all the recent talk about flak/cloud defense. It's purely speculative.

> blow up one target once

For capital assets that takes billions and years to replace like carriers, subs, supply ships, long range bombers, awacs, critical infra nodes all you need to do is blow it up once. It doesn't take a huge pool of hypersonics to essentially dismantle major US force projection capabilities.

> you just won a nuclear response

Why? Primary motive is deterrence, but with conventional forces. And if it comes down to actually exchanging conventional hits, it will follow escalation ladder, no need to cripple, or cripple to point of existential threat that warrants moving to nuclear.

I’m not sure there’s much difference between the Russians using air-launched cruise missiles (with ranges of hundreds to potentially thousands of kilometers and almost always capable of carrying a nuclear warhead) launched from their Tu-95 Bear strategic bombers (equivalent to the B-52), which Russia has done several times now in Ukraine.

I think the difference is that air launched missiles could carry nuclear payloads but usually don't, while ICMBs could carry non-nuclear payloads but usually don't. All kinds of countries have been using air launched missiles all the time which at least on average tells us that every time one is fired it won't(shouldn't) have a nuclear payload. ICMBs on the other hand have never been used against anyone, and their stated goal for existence is carrying nuclear payloads - so if you see one coming your way you can assume it's a nuke, even though technically it doesn't have to be.

> So, because of this game-theoretic equilibrium, any use of the stratosphere for ballistic weapons delivery is effectively forbidden — even though nobody's explicitly asking for it to be.

Interesting! SpaceX was hoping to one day use Starship for quick intercontinental flights. I wonder if this unspoken rule would make that prohibitive?

Unlikely, as those flights would be scheduled and the launch site publicized. It wouldn't absolutely preclude a masked nuclear strike, but that would be possible already with space launches.

It'd also be a pretty shitty first strike, since you'd be limited to the count of starships scheduled to launch (and likely only ones headed generally in the direction of your target if you really want to mask it) at about the same time. So, probably just one or two, at best. Meanwhile, you'd need at least dozens (of missiles—more warheads) to have any hope of substantially reducing a major nuke-armed opponent's capability to retaliate.

Not remotely worth the complexity of setting up and executing. Maybe worth it against an opponent with extremely limited launch capacity (North Korea?) but that's a pretty niche application.

Until we have some magical non-polluting rocket fuel, I can't imagine intra-planetary rocket trips ever becoming permissible. Planes are bad enough.

Ignoring production, hydrolox would work, not that spacex are going down that road

Oh interesting! Rocket science is cool.

There could also be effective anti-missile defenses, which are currently politically impossible due to the fact that developing them puts you outside of the effectiveness of deterrence.

take a look at https://en.m.wikipedia.org/wiki/Prompt_Global_Strike

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