Missile defense is NP-complete

https://smu160.github.io/posts/missile-defense-is-np-complete/

by O3marchnative • 4 months ago

382 423 4 months ago

smu160.github.io

dboreham• 4 months ago

It's been known since the 1960s that effective anti ballistic missile defense is impossible.

trollbridge• 4 months ago

A lot of things involving rockets and putting things in space have changed since the 1960s.

skywhopper• 4 months ago

Have they, really?

* Small rockets can now land themselves.

Anything else?

BoredPositron• 4 months ago

Observability has changed in most other ways we have regressed.

XorNot2• 4 months ago

That's true. And while I disagree with the parent comment, ICBM interception remains enormously problematic and likely will remain so until directed energy weapons get really cheap.

Fundamentally the rocket equation and orbital dynamics really fight you on this.

It's a lot less "can't be done" versus "would be financially untenable to build and maintain even when the objective is nuclear defense".

cpgxiii• 4 months ago

There are several different levels of ballistic missiles.

ICBMs, for which the GBI is intended, are the most challenging to defend against and show the least interceptor success.

In contrast, we do have some pretty definitive evidence that theater and "lower" MRBM/IRMB ballistic missiles can be intercepted successfully. If you define "effective defense" as "most missiles that would cause damage are intercepted", then it is clearly possible with current technology. If you define "effective defense" as "all missiles are intercepted", then it remains beyond the current technology.

hedora13• 4 months ago

If you define "effective" in terms of cost ratios: R = (cost of defense system + cost from failed intercepts) / (cost of attack system)

then N < 100 is well beyond current technology, regardless of whether the defense system is perfect or non-existent.

There's no magic Pareto-optimal point where investing the right amount in missile defense means that starting a war against a medium-sized country makes economic sense. Russia figured this out in Ukraine, and the US figured it out in Iran.

Israel's genocide worked pretty well tactically, but is a long-term strategic disaster. If the US continues to be a democracy, polls say that it will cause us to withdraw support sometime this decade. Also, it only works if you have an incredibly asymmetric fight.

zabzonk• 4 months ago

Oh, I thought this was going to be about the old trackball arcade game. Or perhaps it is? Same sort of rules? The maths is going so far over my head I can't hear the whoosh.

gs17• 4 months ago

I expected that too, but it's about the inspiration for the game, I guess. I was trying to figure out how you encode computation in the game.

delichon3• 4 months ago

Add multiple decoys and the missile math tends to become an argument for the importance of preemption. Han shot first for a good reason.

busterarm2• 4 months ago

Careful. Preemption takes many forms, some of them many would find unpalatable.

gos9• 4 months ago

Unpalatable preemption is generally better than reentry vehicles coming down your chimney.

XorNot2• 4 months ago

But it's also the basic l basis of deterrence and the destabilizing nature of ICBM defense: relying on interceptors presumes the war happens.

blitzar2• 4 months ago

Those schoolgirls were obviously going to be a problem for the US in the next 20 years.

heyitsmedotjayb2• 4 months ago

Preemption is a propaganda lie.

hedora13• 4 months ago

If you haven't, watch House of Dynamite.

Sadly, the Trump Administration concluded we should build exactly the defense capabilities described in the film.

They even cited it by name as a good roadmap for the Golden Dome, so I know they read the title. I guess their reading comprehension levels are extremely low.

marginalia_nu• 4 months ago

The game theory of it is the prisoner's dilemma.

Preemtive betrayal is a terrible strategy if there are more than two parties in the game, and they are allowed to cooperate.

You have to be one heck of a smooth conversationalist to convince them to take a number and patiently wait in line to be the ones to be attacked next.

If you're the guy that the others in the room know shoots first, you're also the guy the others in the room will shoot when he's reaching for something in his jacket pocket.

delichon3• 4 months ago

The prisoner's dilemma leads to mutual defection as the dominant equilibrium strategy in the one-shot version. Cooperation emerges as the equilibrium on repetition. The Han Solo gunfight is literally the one-shot version. When countries go to war that calculation is more complicated.

jmyeet3• 4 months ago

If you haven't, I'm going to recommend you to listen to an episode of Dan Carlin's Hardcore History, specifically The Destroyer of Worlds [1].

Why? Because it goes into the change in strategic thinking brought on by the atomic age (and, soon thereafter, the thermonuclear age). And there was an element of US strategic thinking that argued for a preemptive strike against the USSR.

The episode also goes into the arguments for and against the development of the hydrogen bomb, a weapon that could never really be used and arguably not even necessary when we already had the atomic bomb.

The outcome of those debates shaped American foreign policy from 1945 to the present day.

[1] https://www.dancarlin.com/hardcore-history-59-the-destroyer-...

delichon3• 4 months ago

  With the Russians it is not a question of whether but of when. If you say why not bomb them tomorrow, I say why not today? If you say today at 5 o'clock, I say why not one o'clock?  -- John von Neumann, ~1950

On the one hand he was one of the smartest people in history. On the other, his home country had recently been conquered by the Red Army so he may have been a little biased.

151553• 4 months ago

hydrogen bomb, a weapon that could never really be used and arguably not even necessary when we already had the atomic bomb.

Two-stage designs are far more cost-effective and compact.

jandrewrogers7• 4 months ago

Decoys are greatly over-rated in ballistic missile systems. Sensors are so good at discriminating decoys from warheads that decoys are largely ineffective and have been for decades. This has borne out in Ukraine.

A decoy sufficiently sophisticated to look real to good sensors will have weight and characteristics that approach that of a real warhead, at which point you might as well add another warhead. Decoys only make sense if the marginal cost of adding them is low.

srean11• 4 months ago

I would like to understand this more.

How are decoys discriminated? The acceleration due to gravity is the same for all. Radar reflectance could be manipulated. Drag and lift perhaps, but can't those be matched with the real thing ? What is it that gives up a decoy as a decoy ?

Yes I can distinguish a falling feather from a falling lead-shot. The more interesting questions is can one not make a featherweight that falls like lead-shot, reflects like lead-shot and be cheaper than lead-shot.

For a warhead decoy ten times lighter it needs to present an area ten times smaller to maintain drag induced deceleration parity. For radio parity the decoy needs to reflect more the actual warhead reflect less. Metal coated kevlar ribbons on the decoy might do it.

What I find interesting is that the curse of rocket equation makes decoys pretty expensive to propel. So if I am forced to incur that cost anyway, might as well put a real warhead on that.

heyitsmedotjayb2• 4 months ago

Would be interesting to know how the probabilities change once all your X band radars are destroyed. And then again how they change when all your L band radars are destroyed...

ErroneousBosh• 4 months ago

And then again how they change when all your L band radars are destroyed...

Connection reset by Yugoslavs with microwave ovens

jsw972• 4 months ago

The author explains that this problem is actually adversarial, in the sense that the attacker gets to observe defenses and allocate warheads and decoys accordingly.

Thinking of our current circumstances, this suggests another cost of war: our offensive capabilities, as well as our defensive capabilities become more observable. Our adversaries are studying our strengths and weaknesses in Iran, and they will have a much improved game plan for countering us in future conflicts.

vasco• 4 months ago

If we really want to put a certain hat on we can also say those adversaries have an incentive to not prevent (or even incentivize) those wars for that same reason. Even if that's by helping along a guy that is easy to manipulate through a childlike ego become president.

testaccount282• 4 months ago

there is a benefit as well, though, as it makes your threats credible.

SegfaultSeagull• 4 months ago

Or perhaps they will learn they are outmatched, lack the resources and technological capabilities to compete, and deterrence will have been established.

biker142541• 4 months ago

History would suggest otherwise; rarely is this ever the case.

pjc504• 4 months ago

Iran has always known that the US is a higher tech nation, but you should not just expect them to surrender on that basis.

varispeed3• 4 months ago

You miss the fact that many adversaries will not act rationally.

dlisboa7• 4 months ago

Very few countries lack the technological capabilities to produce these kinds of drones.

What most countries don't have is, for lack of a better term, the resolve Iran has shown. Venezuela could have built drones and resisted just the same, but it's internally divided enough that it was possible to strike a deal with an inside faction and have a coup from within.

nerfbatplz3• 4 months ago

The Iranians just hit an F35 with a proverbial box of scraps they put together in a cave. The Chinese military must have experienced collective euphoria when they saw that.

don_esteban10• 4 months ago

There is a huge difference between 'deterrence' in the sense of deterring a country from taking aggressive action it might have otherwise considered, and 'deterrence' in the sense you are using here (surrender without fight, we are so much stronger than you).

elzbardico9• 4 months ago

Iran can establish deterrence with asymetric means and let's not forget, that contrary to what most americans think, Iran is not a backward hell hole like Somalia or Afeganistan. For a third world country we could say they have a competent R&D infrastructure, with a good number of STEM graduates every year (with roughly half of them being woman, which shows they are casting a wide net for talents).

They also have a lot of leverage points in their geography, in the fact that the US is at a historical low point in its military capabilities.

US and Israel strategy seems to be to completely destruct Iran's economy, but the problem is that this is a game where they can also shoot back.

1234letshaveatw4• 4 months ago

That seems like an acceptable trade off to get some real world experience with what works and what doesn't with regards to massed drones and swarming. There is a lot we can learn in this conflict with relatively low stakes

lejalv2• 4 months ago

Stakes for whom?

100 kids got murdered the first day of this "low stakes" war

myrmidon6• 4 months ago

This is absolutely true, but there is a strong counterpoint: You also learn the limits of your own systems and how to operate them most effectively yourself (and better than adversaries can, too).

Just to pick a recent example: Russian air defense in the early stages of the Ukraine war was dismal (more specifically: defense against big, slow drones like Bayraktar), despite having sufficient AA capability "on paper"-- the war allowed them to visibly improve.

I'd expect much more value from validating and improving your equipment and its handling than the actual "cost" of revealing its capabilities to adversaries in almost every conflict.

neutronicus• 4 months ago

"Data moats" are a problem for military tech, too, I guess.

dlisboa7• 4 months ago

There is an assumption here that the value in improving defenses is the same as improving offensive weapons. That is not the case in the assymetry that drones provide and Russia is the first example.

Russia has not been able to improve AA capabilities to the point where it's "safe", for any definition of the word, neither has Israel. Israel and Gulf states often tout over 90% interception rate yet it's really at the mercy of Iran to not target their most vulnerable sites. If Iran was routinely targeting desalination plants and refineries it wouldn't matter if it was 99%: one hit is all it takes. Similarly Russia cannot keep Ukraine from targeting their oil infrastructure.

Air defenses need to be 100% to prevent physical, economic and moral damage. That is an impossibility.

energy1237• 4 months ago

Practise is good, but exhaustion is bad. Russia is getting exhausted, which is why their influence collapsed in Syria, Azerbaijan and Armenia, allowing the US to overtake those vacuums.

The US in WW2 staged their 20th century by letting others (China, South East Asia and the British/Soviets) get exhausted first. This was more an accident of geography rather than US grand strategy, but it worked all the same.

roysting2• 4 months ago

There is no amount of math that can make up for the lopsided dynamic of hypersonic missiles. The only reason the “iron/gold dome” con job was even plausible to plunder trillions in U.S. Monopoly money was because missiles were crude, slow, and not MIRVed or had decoys at one time. That was a long time ago though.

MIT Prof. Emeritus, Theodore Postol, has been trying to warn about this basic, mathematically proved fraud for many years now. However between the indifference because the party was still in high swing and the plundering was making people rich who could pay professional lobbyists/liars, very few people were paying attention or really cared, even though it’s clear fraud and just a false confidence; as is the objective of a con job, which comes from “confidence trick”.

There are several lectures he gives and more recent appearances on various YouTube channels where he clearly describes the inherent fraud in “missile defense”.

Here’s the synopsis; it’s like trying to prevent sand from hitting you once someone has thrown a fist full of dry sand at you.

It’s basically just the end game in a long history of American snake oil salesmen turned missile defense salesmen. You get useless junk, they run off with your wealth.

maxglute8• 4 months ago

much more value from validating and improving your equipment and its handling than the actual "cost" of revealing its capabilities to adversaries in almost every conflict.

The value of carrying a big stick is lost when others see the stick breaks after a few swings. There's value in maintaining military kayfabe - revealing hand in sideshows and losing deterrence for main events as result can be much costlier down the line. What was learned that wasn't already known and deliberately avoided in polite conversation?

jsw972• 4 months ago

Definitely, you have to weigh the benefit of experience against the cost of revelation. (And all the other costs of course.)

don_esteban10• 4 months ago

The defense against Bayraktar at the beginning (the big column to the north of Kiev) was dismal because AA assets were turned off, not because they were unable to shoot Bayraktars.

The problem was command and coordination.

Darwin worked and Russians learned (as did Ukrainians).

Regarding your last point: In peace time, you want to prioritize hiding your true capabilities (perhaps inflating them in (misleading direction) to deter them from attacking). Once the ware breaks out, you want to improve your capabilities as fast as possible.

thaumasiotes• 4 months ago

I'd expect much more value from validating and improving your equipment and its handling than the actual "cost" of revealing its capabilities to adversaries in almost every conflict.

That depends on how far out of touch your reputation was with the facts. If you're not able to live up to your preexisting reputation, being tested is all downside even if it improves your actual capabilities.

p00dles• 4 months ago

who is our/us?

renewiltord• 4 months ago

Veterancy is more valuable. Observers can tell only a certain amount about what you can do, but you know your limits much more deeply and you can adapt. In fact, it's much better we get our nose bloodied repeatedly now¹ so that we learn how fallible we are and make sure our processes involve aircraft carriers not being put out of commission during wars because of dryer lint fires.

¹ in a military sense; in a geopolitical sense obviously it's clear that Iran has been a misadventure

DivingForGold• 4 months ago

Did I miss this ? Missing from the discussion is that Iran's cluster munitions in each single missle have absolutely overwhelmed Israels defense and would likely do the same to US military as well. Also to consider, Iran's $20,000 drones versus our $1 million dollar interceptors.

wavefunction• 4 months ago

You could counter multipayload missiles by hitting the missile earlier in its trajectory before the payloads deploy, that was the plan for MIRV nukes but it requires usually forward interceptors or perhaps energy weapons we don't yet have.

maratc8• 4 months ago

Cluster munitions are great against infantry in open field; less so against population centres equipped with advance warning systems. As it stands, they fail to even cause the damage worth offsetting by firing interceptors. The damage these inflict on Israel is not unsustainable, and they don't do much to create deterrence.

Given a choice of conventional 500-800 kg warhead or cluster munitions warhead, I think that the nations in the current conflict would prefer being on the receiving end of cluster munitions (as a less bad option) every time.

baxtr3• 4 months ago

While this is true it's also impossible to avoid.

So you could also argue that this war will help the US to gain experience it didn't have before which might be favorable in future conflicts with parties that didn't have this experience.

jmyeet3• 4 months ago

In strategic circles, this was a common thought in the 12 day war: Iran was essentially mapping and testing defenses.

As evidence of this, the US was forced to hastily move THAAD ground station radar from South Korea because Iran destroyed a bunch of them in the Gulf [1][2]. Bear in mind there aren't many of these and they cost half a billion dollars each.

Further evidence of this is how quickly it happened. Iran most likely had detailed contingencies and battle plans for this kind of event.

As an aside, this is what militaries do. They plan for things. So whenever you see some conspiracy about how government X reacted to situation Y quickly and thus had foreknowledge, you can ignore it. Military planners are paid to make up fictional situations and figure out how to respond. That's what they do.

Weapons are the ultimate export. You use them and blow them up and the customer has to come back and buy more.

[1] https://www.theguardian.com/world/2026/mar/11/redeployment-u...

[2] https://www.cnn.com/2026/03/05/middleeast/radar-bases-us-mis...

jandrewrogers7• 4 months ago

Iran destroyed a bunch of them

If by "a bunch" you mean one.

EthanHeilman• 4 months ago

It doesn't have to be, defender reveals everything and attacker chooses best strategy.

1. The defender could use both electronic and physical decoys, use air and sea mobile platforms that are always in motion and are difficult to track.

2. The defender can fire at decoys, to convince the attacker the decoys work when they don't.

3. The defender could mix in cheap decoy interceptor missiles that miss so the attacker concludes defenders need 10 missiles to intercept when the real number if 3 and the attacker thinks the defenders are running low on interceptors, when in fact the defenders have held most of their interceptors in reserve.

4. Defender can pretend that expensive systems have been destroyed so that attacker adapts their strategy. For instance, if your defense hinges on a small number of extremely expensive fixed X-band radars and the attacker targets them. Allow some of them to be appear to be destroyed when in fact, you have disassembled them and moved them somewhere else to use later in the war.

I see no evidence anyone is doing any of this today, I'm not making any sort of claims about deception operations in the current conflict.

dotancohen• 4 months ago

Many historical wars have been won by deception.

Sun Tzu taught us: When you are weak, appear strong. When you are strong, appear weak.

simonsarris• 4 months ago

On the other hand, the best way to improve your capabilities is to use them frequently.

The Russian army assumed a state of readiness for the Ukraine invasion that turned out to be, well, less. Their special forces floundered, their logistics were (are still!?) unpalletized - using bespoke metal containers and wooden crates! Whereas the US military learned an awful lot from its (mis)adventures over the last decades.

elzbardico9• 4 months ago

I think Russia's strategy fault was more that they didn't expect the amount of support Ukraine could coalesce in such a short time.

standardUser2• 4 months ago

Take China for an example. No one knows China's true military capabilities, because they're rapidly evolving and because they virtually never use them. If there's an element of surprise to be had, they have it. But that cut's both ways, because China itself doesn't have experience exercising those capabilities. The learning curve could be noticeable. Meanwhile, no one doubts the ability of the US military to execute.

elzbardico9• 4 months ago

Basically the only country left in the world with expeditionary capabilities is the US.

It is hard to compare this with China. Different goals and philosophies.

srean11• 4 months ago

China uses wars like these to test their equipment for example the s300 knockoffs. These were not effective in Iran nor in Pakistan. I am sure the Chinese have made a note of that and debugging the failure.

grafmax2• 4 months ago

"Our" adversaries, huh? There are more people in our country than pedophile billionaires, but it's this group starting the wars, murdering civilians, and producing generations of "adversaries".

shiroiuma2• 4 months ago

The pedophile billionaires are your leaders, because you voted for them. You have no one to blame but yourselves.

GeorgeWBasic• 4 months ago

"Our adversaries" are in the US government, or is this not crystal clear by now?

ReptileMan• 4 months ago

On the other hand the Air force is getting the workout of their lifetime. Which could come in handy. The low bodycount among US military so far makes the whole clusterfuck just and expensive training program.

wodenokoto• 4 months ago

That’s why Russia cut cables in the Baltic Ocean and flew a drone around Copenhagen airport.

That’s why StarCraft players sends “scouts” into enemy bases in the early game.

RobertoG• 4 months ago

This is a problem with a know solution, already applied by many in the world: don't start wars.

Specifically: don't start wars thousand of miles away of your borders.

u_sama• 4 months ago

Great nerd title, the maths made me nostalgic as I haven't seen a Sigma/Pi in a few years

owenmarshall4• 4 months ago

Two more sobering axes to introduce: cost and manufacturing capability.

Numbers are hard to find for obvious security reasons, but using the numbers most optimistic to the defender[0] suggests an adversary using a Fatah type hypersonic is spending 1/3rd the cost of an Arrow interceptor, and is launching missiles that are produced at a much faster rate. Interception is deeply asymmetric in favor of the attacker.

[0] https://www.jpost.com/israel-news/defense-news/article-82314...

jvanderbot2• 4 months ago

Ah yes, but then you also have to add GDP + targetting/defense radii.

Great Britian alone has 10x the GDP of Iran. So an interceptor costing 10:1 is (at first approx) breakeven just for GB, who would have to intercept much less than the total manufacturing capability of Iran anyway.

Then you have every rich nation surrounding Iran as well. Let alone the USA who cannot be reached but throws their weight behind interceptions.

And finally "total manufacturing capability" is set to decline in any prolonged engagement with an Iran-like nation, but GB, western EU, USA, et al, are likely to only increase production if an engagement played out.

The math looks catastrophic on paper at 10:1, but I sincerely doubt that's the right analysis. An interceptor is worth what you're protecting, not what the attacking asset costs, so long as you can keep producing them.

Thaxll• 4 months ago

This is wrong, for example Iran have thousands of Shahed drones, they cost almost nothing to build, to intercept just one the ratio is way way higher that 1:10. A single patriot missile is in the multi millions $ range.

orwin2• 4 months ago

total manufacturing capability" is set to decline in any prolonged engagement with an Iran-like nation

That was what Russia thought about Ukraine. Effectively, they needed East European tanks and munitions for the first two years, but munitions production ramped up, and now they produce more per year that what they received over two years. A resource-rich country like the Iran that is effectively fight a death war (that's the controlling party belief) can keep up a very long time. The fact that the US tried to get the Kurds and the Baloch/Sistanni involved show that they are well aware that the way out is through a permanent civil war and the country fracturation. And imho, while Kurds accepting to be betrayed by the US for the third time in less than two decade won't have any real long term impact, an independent Baluchistan can easily destabilise Pakistan. Also, that would be a third country in the area in which the Hanafi jurisprudence is pushing hard towards Deobandi/Salafi, and personally I'd rather have any Shi'a school than that.

bluGill3• 4 months ago

There are too many potential attackers though, and not everyone is sane. So you don't really get a choice about it. The cost of the interceptors needs to be considered in relation to the cost of what it protects. If the interceptor means an attacker doesn't kill my kids then it was worth the cost. If the interceptor keeps a multi-million dollar building around then interceptor at a million dollars is still cheap, even if the missile it takes out was only $100.

Yes you should use diplomacy to ensure war doesn't happen in the first place. However if it does: they will send cheap drones and missiles at you in large quantifies.

ceejayoz3• 4 months ago

If the interceptor keeps a multi-million dollar building around then interceptor at a million dollars is still cheap, even if the missile it takes out was only $100.

Not if it means you can't intercept the next one hitting much a more valuable/critical building.

wat1000010• 4 months ago

Unfortunately, necessity doesn’t imply possibility. It could simultaneously be true that you must build interceptors to protect yourself, and that you can’t build enough.

It only makes sense to consider the cost of what’s protected if it’s actually protected. If your million-dollar interceptor protects a multi-million-dollar building from a $100 missile, and then that building is hit by a second $100 missile, was it worth it?

That’s the math that has prevented missile defenses from being deployed on a large scale despite being technologically possible for well over half a century now, and despite the fact that a single interceptor might be saving an entire city from a nuclear warhead.

An interceptor costs at least as much as what it intercepts. Take into account miss rates and the cost of defense is a multiple of the cost of offense. Add in the fact that the attacker can concentrate an attack but the defender has to defend everywhere, and multiple warheads on a single missile, and the cost of defense multiplies further.

If defense costs 10x more than offense (a conservative estimate, I’d say) then that means you need to dedicate 10x of your economic capacity to it than your attacker does. If your attacker dedicates more than 10% of what you can put into defense, you lose. Defense can work, but it needs to be against a far weaker enemy. Thats why the most prominent example is Israel defending against neighboring non-state actors. Israel is wealthy enough, and the groups shooting at them are poor enough, that the math works out in the defender’s favor. Iran is a rather different story. And of course defending the US against the likes of Russia and China is a fever dream.

maratc8• 4 months ago

That's a false comparison. You want to compare between the actual options you have, which are either (a) firing an interceptor (or several); or (b) repairing the damage caused by a non-intercepted missile.

owenmarshall4• 4 months ago

Your first option comes with the major caveat that each interceptor you fire comes from a limited stockpile whose replacement rate[0] today isn't sufficient for even going 1:1, let alone accepting that multiple interceptors are required.

I'd say the real options in the near term when faced with an inbound missile is a) deciding to deplete your stockpile of interceptors with an incredibly limited replenishment rate; or b) risking a hit to a lower-value target.

Could the US go to a war economy footing and scale production? _Maybe_? I'm not entirely convinced the US can stomach the costs.

[0]: again, numbers are hard to find, but https://www.lockheedmartin.com/en-us/news/features/2026/Lock... gives a flavor of just what defenders are up against.

wat1000010• 4 months ago

It’s far more complicated than that. The choice is often between firing an interceptor against this missile aimed at this target, or firing that interceptor against the next missile aimed at a target you can’t yet know. Because unless your production capacity far outstrips theirs, you’re going to run out first.

keybored5• 4 months ago

Sobering how asymmetric Iran’s attacks on Israel are after Israel attacked Iran.

jonaslanglotz• 4 months ago

Calling a Fattah hypersonic is a misleading claim. It is simply a ballistic missile that reaches hypersonic speeds, which is different from a true hypersonic weapon in its flight path and ability to maneuver. This distinction is important because it makes it significantly easier to shoot down than something like a hypersonic glide vehicle or hypersonic cruise missile.

But I agree with your point that it does remain difficult to intercept and poses the shot-exchange problem.

Gravityloss• 4 months ago

Depends on the school. https://www.reddit.com/r/NonCredibleDefense/comments/1at8gj4...

nerfbatplz3• 4 months ago

There's videos from Israel showing Iranian missiles performing AD evading maneuvers that western media was saying was impossible a few months ago.

shdudns2• 4 months ago

But they can steer, videos show that.

This really shouldn't surprise anyone. Iran graduates as many engineers as the US (70% women), but few of them are working on front-end A/B optimization of some boutique dating site.

And, having taken grad classes with folks graduated from Iranian universities, their training is excellent. The Persian kids were always at the top of their class.

EDIT: for the record the class I merely audited was graduate level (rational) mechanics - the class par excellence if you're going to build a hypersonic.

Some observations:

Half the class was Chinese, the academically better half was Persian.

I was the only Westerner (albeit also foreigner)

The girls were wearing veils.

According to the professor, the best mecanist (?) of the 20th century, Clifford Truesdelle, was an American

The Professor was Iranian.

hedora13• 4 months ago

Currently, we're using $1M interceptors to take out $30K drones. This asymmetry is here to stay.

The end game probably involves < $1000 autonomous drones that target IR or RF and drop something like hand grenades. On the defense side, there would similarly-priced interceptors with bolas, backed up with sharp-shooters for important targets.

At that point, it turns into a logistics problem that's much easier for the attacker than the defender. Iran's already demonstrated that one successful drone can do $100B-1T in damages, so a hit rate of 0.1% means a 1:100K cost:damage ratio.

owenmarshall4• 4 months ago

This leans towards my belief that the US is fundamentally fighting last century's war against adversaries that have _massively_ evolved.

Look at the Ukranians: they are currently fielding an entire suite of counter-drone tech: fast pursuit systems to hit Russian drones on launch, cheap FPV drones for last-mile intercept, integrated radar/acoustic monitoring to target and respond to launches... and of course, the Russians are responding with IR floodlights and air to air launchers on their drones, or even just launching a bunch of cheap foam decoy Gerbera's in the middle of their Shahed's to soak up intercepts. Meanwhile, the front lines are basically static -- any infantry from either side that tries to go into the kill box gets picked off by loitering drones.

And the best the US can field today is "$1mm per Patriot" or "cover a tiny area with Land Phalanx (which also costs something like $4k/second burst)".

pc865• 4 months ago

What Iranian drone did a trillion dollars in damages?

I'm not saying the general thrust of your argument is wrong, quite the opposite. But that's a big number for one drone.

energy1237• 4 months ago

The best missile defense is offsense: degrading the launchers, stockpiles and defense industrial base, with cheap stand-in munitions after SEAD, leveraging air and intelligence superiority. Expensive interceptors are only a stop-gap that buys you time for the offensive degradation. Expensive stand-off munitions, likewise, are a short-term stopgap until SEAD is complete.

hedora13• 4 months ago

Offense doesn't work at scale.

As the cost of drones goes to zero, the expected damage you take is roughly proportional to how much you have to lose. This means larger / richer economies cannot win these sorts of wars. To see what I mean, check out this desalination plant map:

https://www.theguardian.com/world/2026/mar/23/iran-threat-to...

It doesn't help if your commander in chief is incompetent and your invasion strategy involves treating desalination plants as legitimate military targets.

Of course, blowing up desalination plants in the middle east don't hurt the US all that much, but blowing up industrial supply chains does. We're something like 4 days away from a global chip manufacturing industry shut down (barring some logistic miracle, since we recently sold off our strategic helium reserves).

shdudns2• 4 months ago

So what Iran did in the Gulf

Cheap drones overwhelming defenses until the billion dollar radars and airfields got hit.

Then methodically hit everything according to a plan that forces allied forces to retreat to reliable water sources.

Whatever one thinks of Iran, the way they're waging this war is a masterclass in strategy.

littlestymaar2• 4 months ago

And that's why nuclear deterrence is so key: the enemy can never be sure to destroy everything before being hit once.

The Russian invasion of Ukraine really reminded everyone that nuclear deterrence is a nice thing to have for you security, and I suspect the Israelo-American attack on Iran is going to be the nail in the coffin of nonproliferation.

I expect countries like Brazil, Japan, South Korea or even Taiwan or Vietnam to have the bomb within ten years at this point.

And given the current war and the dramatic consequences ahead, I now think that the world would have in fact been safer had the Mullah's regime actually got the bomb instead of playing the “under the threshold deterrence” game.

srean11• 4 months ago

Game theory would be useful for these kinds of modeling.

Perhaps the government should have and advisory body that employs the smartest mathematicians for running these scenarios. Of course a lot of randomness needs to be modeled too. Wonder what would be a good name for such a body :)

Paradoxically, if anyone leaks unpalatable information from the inside that would be a problem for the government.

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

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

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

Maro• 4 months ago

" .. the smartest mathematicians for running these scenarios .. "

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

Claude Shannon called him "the smartest person I've ever met", a common opinion.
Von Neumann founded the field of game theory as a mathematical discipline.
.. leading him to a large number of military consultancies and consequently his involvement in the Manhattan Project.
In 1950, von Neumann became a consultant to the Weapons Systems Evaluation Group..
In 1955, von Neumann became a commissioner of the Atomic Energy Commission (AEC), which at the time was the highest official position available to scientists in the government.
In his final years before his death from cancer, von Neumann headed the United States government's top-secret ICBM committee..

srean11• 4 months ago

The Martian.

Towards the end of his life as cancer metastasised in his brain he would ask his visitors to give him sums to do to reassure himself that he was still there. Towards the end he wasn't and couldn't. One of the saddest things.

quotemstr• 4 months ago

The sole mention of directed energy:

Directed energy has been proposed as a cost-effective alternative, but introduces its own scheduling constraints — dwell time, platform coverage, atmospheric degradation — with similar scaling issues

The author is doing the thing where a writer tries to bamboozle the reader into a conclusion without having to prove it by overwhelming the reader with nouns. Life is too short for shitty gosh gallops.

myrmidon6• 4 months ago

You are basically complaining that the article is not about a your preferred, different topic.

Directed energy defense does not really compete with a system like GMD at all, because the range is extremely limited by comparison.

The US might be able to justify throwing a few billion at a few dozens of ICBM interceptors stationed in a handful of sites, but protecting every potential target (city, military base) with some kind of laser array is obviously unrealistic.

tonnydourado• 4 months ago

Gotta say, did not know direct energy weapons were actually leaving science fiction and entering the real world yet, but it seems they're. It's obviously not star trek level, but it's way more advanced than I expected

OrangePilled4• 4 months ago

Bearing in mind the three constraints quoted, which of these do you think a country's deployed directed-energy weapons (e.g., US, Israel, Russia) would be useful against:

https://missilethreat.csis.org/country/iran/

hedora13• 4 months ago

You don't really have to guess. None of those countries are using directed energy weapons, and they're all repeatedly getting hit by Iranian technology (so they have an incentive to test whatever they have).

femiagbabiaka• 4 months ago

could use some investigation of the ukranians techniques -- the number of interceptors the U.S. used within the first four days of the war eclipsed the total amount Ukranians have had for the war

OrangePilled4• 4 months ago

"Lessons US and Gulf could learn from Ukraine’s air defence warriors"

https://www.thetimes.com/world/russia-ukraine-war/article/us...

"Ukraine’s low-cost Shahed killers draw US and Gulf interest, but a wartime ban blocks sales"

https://apnews.com/article/iran-ukraine-shahed-russia-drone-...

"Ukraine Helps U.S. Bases in the Mideast With Stopping Drones"

https://www.nytimes.com/2026/03/09/world/middleeast/ukraine-...

"Ukraine deploys units to five Middle East countries to intercept drones"

https://www.reuters.com/world/europe/ukraine-deploys-units-i...

Maken• 4 months ago

What the USA learned from Ukraine is that the Shaheds are amazing and they want them too [1], apparently.

[1] https://en.wikipedia.org/wiki/Low-cost_Uncrewed_Combat_Attac...

energy1237• 4 months ago

What is the steady state? Assume you have two competent superpowers, both researching missile offense and defense, over the next 1000 years. What are the asymptotics of the interception rate from 0 to 1000?

bob1029• 4 months ago

The steady state would look like a sinusoidal signal. This is more of a cycle than a hill climbing thing.

energy1237• 4 months ago

Are you sure there isn't a structural advantage to either offense or defense that will reveal itself with more iterations, and we won't converge to either 0% or 100%?

adampunk2• 4 months ago

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

That’s the steady state. Interceptors are expensive; missiles are (relatively) cheap. There’s no sine wave or cat and mouse game. If you’re trying to defend against a peer, missile defense loses.

energy1237• 4 months ago

I'm talking about interception probability, not the relative cost. I get that interceptors will probably be more expensive indefinitely (unless we start putting lasers into orbit to get around atmosphere, or something unexpected like that).

jmyeet3• 4 months ago

Pardon the pun but this is an arms race and the defenders are going to lose. There are broadly five classes of missiles (one isn't a missile per se):

1. Ballistic. These are traditional rockets, basically. While rockets are designed to reach orbit or leave the Earth, a ballistic missile basically goes straight up and comes down. The higher it goes, the further away it can get because of the ballistic trajectory and the rotation of the Earth.

Ballistic missiles are most vulnerable in the boost phase ie when they're just launched. Since you have little to no warning of that, that's not really helpful.

But one weakness of ballistic missiles is you pretty much know the target within a fairly narrow range as soon as they launch. That's the point of early-warning radar: to determine if a launch is a threat so defenses can be prepared.

Attackers can confuse or defeat defenses in multiple ways such as making small course corrections on approach, splitting into multiple warheads, using decoys for some of these warheads, deploying anti-radar or anti-heat seeking defenses at key points and breaking into many small munitions, sometimes called cluster munitions on the news but traditionally that's not what a cluster bomb is or was. In more sophisticated launch vehicles, the multiple warheads can be independently targeted. These are called MIRVs (multiple independently targetable reentry vehicles).

Economicallky, depending on range and capability, a ballistic missile might cost anywhere from $100k+ to $10M+.

2. Rockets. Militarily this is different to a rocket in a civilian context. It's not much different to a hobby rocket, actually. Often these are "dumb" but some have sensors and guidance capability or might be heat-seeking.

These tend to be incredibly cheap to produce and not terribly accurate but that's not really the point. The point is they're cheap and easy to produce and the interceptors are much more expensive.

3. Cruise missiles. Rather than a ballistic trajectory, these have more sophisticated guidance and travel much closer to the ground, usually to avoid radar. The Tomahawk missile is a prime example of this. These tend to be relatively expensive and much slower than ballistic missiles.

4. Hypersonic missiles. This is a relatively new invention that's kind of like a cruise-ballistic hybrid. It flies in the atmosphere for part or all of the time and, unlike cruise missiles, will fly faster than the speed of sound, usually significantly so (eg Mach 4-10). Such high speed makes interception near-impossible currently.

The big advantage of a hypersonic missile is that it has the speed of a ballistic missiles without the predictability of the target area. Plus it can be retargeted in-flight.

5. Drones (honorable mention). Not technically a missile but they fit in this space regardless. This is basically a scaled up commercial drone with an explosive payload. These are significantly slower than cruise missiles or rockets but can be live-targeted, re-targeted and have a variety of types ranging from dropping hand grenades from a height (eg as has happened in Ukraine) to suicide-type drones that explode on impact.

Drones are typically so slow that you could shoot them down with an shotgun in some cases. But they're incredibly cheap and easy to produce.

sgtsteaks2• 4 months ago

You cannot shoot a drone down with a shotgun. The range on a shotgun is nothing.

Do you know that it actually fires bb's out in a cone shape? If you aim a shotgun up in the air, you are not taking out any drones.

Look up the video of the drone hitting the hotel in Bahrain to get an idea of the speed and altitude.

ultimafan• 4 months ago

I think you and the previous comment are talking about different types of drones- the smaller commercial quadcopters used in the Russia-Ukraine conflict can be shot down with shotguns fairly effectively.

Both sides have been seen with one member of a squad carrying around an issued shotgun in an anti-drone role- the fact that it shoots pellets in a cone is precisely why it's so effective. Skeet shooting is a great example of how relatively small fast moving targets can be hit consistently at range with a shotgun and they are usually using much smaller/lighter pellets with poorer velocity/range, I would assume the loads used in an anti-drone role are bigger.

chasd002• 4 months ago

Maybe the winning strategy is always attack and never be the one defending. That’s unfortunate.

vaporwario• 4 months ago

Not sure if it applies exactly but this discussion brings to mind this saying...

"The loser of a knife fight dies in the street. The winner dies in the hospital."

koakuma-chan3• 4 months ago

Why does a ground based interceptor cost $75M? High idiot index?

hedora13• 4 months ago

$1M, but we can only make 600 / year, globally.

koakuma-chan3• 4 months ago

From the article,

"Each GBI costs approximately $75 million, and as of 2024, 44 are deployed across Alaska and California [3]."

mrguyorama6• 4 months ago

In what world would a specialized, niche, high precision, high readiness rocket meant to loft a very advanced interceptor munition into an extremely high velocity interception ever be cheap?

These things are closing at like mach 20. Physics says that's hard to do. That means it's expensive.

For reference, $75 million is in the realm of a Falcon 9 launch, which is a very cost optimized platform that doesn't have to place a very very precision instrument payload in a very very specific point in space to prepare it for a high energy, extremely difficult interception.

koakuma-chan3• 4 months ago

Does it being very high precision or whatever mean that it must cost $75M per unit? Is it made of gold?

fisherwoman• 4 months ago

Those rockets are lobbed in high arcs and glow in the sky then slowly fall down - they are so slow they almost look like flares.

Your so-called missile defense does nothing at all against a real missile like Iran's supersonic ICBMs which can exceed 24,000+ km/h.

sgtsteaks2• 4 months ago

What are you gonna do when Iran destroys the missile defense system itself, oops already happened

contravariant• 4 months ago

Note that a more complete model would multiply each term by P(track)_j — the common-mode detection-tracking-classification factor developed in the previous section — but the standard WTA formulation assumes perfect tracking.

I'm not sure that is a useful model, or more complete. I don't think you can assign interceptors to undetected missiles, so considering their effect on the value is rather pointless. It's effectively a sunk cost.

Multiplying with the probability also makes no sense from an optimisation point of view. Why would you assign lower value to a target about to be hit simply because you were unlikely to detect the missile?

The tracking probability only shows up in the meta game described at the end, where one side is trying to optimise their ability to hit valuable targets and the other is trying to optimise their ability to prevent that from happening.

maxglute8• 4 months ago

Hence, for one warhead, a defender can launch 4 interceptors and have a 96% chance of successfully intercepting the incoming warhead. Unfortunately, those numbers are optimistic.

This part worth stressing, ceiling for more performant missiles, i.e. faster, terminal maneuvering, decoys are geometrically harder to intercept. Past mach ~10 terminal and functionally impossible because intercept kinematics will break interceptor airframes apart.

AFAIK there hasn't been tests (i.e. FTM series) done on anything but staged/choreographed "icbm representative" targets. Iran arsenal charitably pretty shit, including high end. Hypothetical high end missile with 10%-20% single shot probability of kill requires 20-40 interceptors for 98% confidence, before decoys, i.e. 40x6=240 interceptors for 1 missile with 5 credible decoys.

The math / economics breaks HARD with offensive missile improvements.

Voultapher3• 4 months ago

Lasers. No really, near-future laser systems with adaptive optics and good spotting - for example distributed SAR satellites - dramatically shift that balance [0].

[0] https://toughsf.blogspot.com/2025/05/the-laser-revolution-pa...

gpderetta2• 4 months ago

I doubt a MW laser can reliably intercept a reentry vehicle. A lot of energy is lost through the atmosphere when intercepting a warhead in space, from a land based laser. Once it reenters the atmosphere there might not be enough time. You also need to burn through the heatshield that the warhead is equipped with for reentry.

Even if you can can deliver enough energy for long enough, there is no fuel to burn and it might not be easy to detonate or disable the warhead.

For ICBMs, one idea was to use orbital, nuclear powered lasers to hit the missile on the boost phase.

But that's very much not near-future.

Lasers might still be useful for rockets, drones and cruise missiles of course.

maxglute8• 4 months ago

Maybe for subsonic, high end missiles I'm extremely skeptical. Need 5-10MW to get useful dwell power on high end hypersonic inherently shielded against reentry thermals. Speculative laser defense are infra size defense, not mobile trailer size. Factor in duty cycles (i.e. shots per minute) and it seems dead end. Half of economics of missile defense is mobility - building density relative to threats by moving platforms. Last 2 parts real constraints, high-end adversaries coordinate salvos to arrive in time. Interceptor magazine depth limited = still throw 100s of interceptors to engage multiple targets if required. Lasers = serial visual range engagement. Figure out dwell time + duty cycle to saturate. Hypersonic can go from over horizonal to hit target in 10 seconds, a laser couldn't engage more than 1-2 missiles in that time. Technically 1, because by the time you fried 1st target the 2nd is so close the shrapnel will hit on momentum.

consumer4512• 4 months ago

Lasers are not "all weather" weapons as far as I am aware. Clouds, snow, fog, rain, and just humidity all degrade their performance greatly.

apt-apt-apt-apt• 4 months ago

Try that on my spinning, mirror-coated missile!

dgroshev3• 4 months ago

That goes both ways. Terminal manoeuvring gets difficult as speeds increase, too. Besides, higher tier threats are intercepted outside the atmosphere, where it would be prohibitively expensive (in mass and accuracy) for RVs to manoeuvre.

Your SSPK is way WAY too low. Also, the math on interceptions changes completely with multiple KKVs per interceptor (see NGI).

Decoys don't work even at the highest end (ICBMs), see Chevaline's history and its rapid decomissioning for an example of just that.

maxglute8• 4 months ago

Terminal maneuvering vs interceptor kinematics difficult don't scale same at same rate with speed increase, a few Gs on reentry is magnified on interceptor end, the physics is not fair between attacker/defender.

Higher threats are not exo atmosphere & midcourse that NGI targets, actual speculative high end threats (since we talking about speculative NGI capabilities) are hypersonic glide in upper atmosphere, which NGI can't target. It's even more extreme intercept problem, the intercept math for those class of threats is on paper even more lopsided against defender.

NGI basically ensure US keeps pace with modern penetration aids proliferation, i.e NKR tier adversaries if they ever improve RVs + decoys from shit tier to mid tier. Chevaline was 50 years ago, not really relevant example, since issue was really economics of decoys vs just spamming mirv. Regardless, NGI trying to maintain 3/4/5 interceptor ratio instead of 30/40/50/100s against exo threats, which on spectrum is low/medium end. It does 0 against actual future highend threats of glide phase interception, an entirely different category.

jcul2• 4 months ago

Really interesting.

Forgive my ignorance, but I thought Israel's "iron dome" offered a very effective defense.

Is this just from short distance missiles from neighbouring countries?

This article seems to indicate it's very difficult to achieve a high success rate against multiple missiles.

Admittedly I probably need to read up on this more.

icegreentea22• 4 months ago

There are multiple tiers of missile (and ballistic missile defense).

Especially with ballistic missiles, the longer the range, the faster the inbound warhead will be in the terminal phase (roughly). So longer range ~= faster meaning more difficult to intercept.

"Iron Dome" is the name generally used to describe Israel's lowest tier set of defenses. Very roughly Iron Dome is designed to defend against stuff that you could plausibly fire from the back of a truck, and have a max range of around ~50km.

Very roughly, these were intended to take on something like GMLRS (realistically, massed volleys of unguided rockets) - these are rockets that one or two people could conceivably manhandle, and are traveling in the neighborhood of Mach 2-3. One of the key innovations of Iron Dome is its ability to quickly ascertain and design on which rockets were unlikely to strike valuable areas, and only engage the actually threatening ones.

The next tier up is David's Sling, and then Israel's wider set of high performance anti-ballistic missile systems. Returning the the range <-> speed thing, we'd need something like a medium range ballistic missile to get from Iran to Israel. For something like the Shahab-3, that's like ~Mach 7 during re-entry.

If we step up to IRBMs (so something that China might use to strike at Guam), we're probably talking like Mach 10.

jcul2• 4 months ago

Interesting stuff, thanks for the long and detailed response.

EGreg2• 4 months ago

What happened to Iron Beam / lasers and those vaunted "space lasers" dubbed "star wars"?

hedora13• 4 months ago

Apparently, Iron Beam still exists (or at least was demoed in 2024).

Originally, the lasers were going to be mobile, but now they have to be stationary, so it will work like the game Missile Command, except you have unlimited ammo, but no concurrent shots, and the missiles can't be rotating (like a rifled bullet would).

That's much more feasible-sounding that I'd assumed (coming from low expectations).

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

EGreg2• 4 months ago

I seriously can't wait for this technology.

It can be purely defensive, and shoot down all aerial attacks - drones, etc. over your country's airspace.

So... no wild weasel, no successful air raids, etc. We're back to ground invasions, and frankly, a country can defend against those a lot easier.

And it also means countries not lobbing missiles at each other, and at oil fields and igniting them, or destroying shipping etc.

jandrewrogers7• 4 months ago

The US has deployed operational anti-drone lasers for a few years now, though not widely. They are still quite new but they have several kills. This is probably operational field testing for fine-tuning the design prior to producing them at scale though.

ozgung• 4 months ago

As an alternative formulation of the same problem, maintaining peace has linear cost, completely solvable in linear time and rewards are unbounded for all parties.

OrangePilled4• 4 months ago

If you're looking for a job and are still squeamish about working in the defense industry...I'm sorry to hear about that.

Because, boy, do I think you'll be missing out.

inaros• 4 months ago

I spent some time reconstructing the current US missile defense interceptor numbers. This was done from open source DoD data, CSIS P-21 procurement exhibits, and CRS reports, that are are in depth, non partisan, objective policy analyses written by experts at the Congressional Research Service (CRS) specifically for U.S. Congress members. Also used Lockheed/RTX financial disclosures.

The numbers are pretty bad… Way worse than the headlines suggest. But anyway nowadays, investigative journalism has been decimated....For example experts like Kelly Grieco at Stimson estimated that at 12 day war consumption rates, the entire US interceptor stockpile depletes in 4 to 5 weeks. We are now in week 4...

As of December 2025, CSIS documented delivery of 534 THAAD interceptors and 414 SM-3. The 12 day War burned through around 150 THAADs (that is 28% of inventory) and about 80 SM-3s. The current war has been drawing down from that already depleted starting point for 25 days straight...

Gulf states reportedly expended around 600 to 800 PAC-3 MSE interceptors in the first 72 hours of Epic Fury alone, and that is more than the entire global 2025 production ( about 620 units).

Meanwhile THAAD production is 96 per year….with a recent Lockheed commitment to quadruple to 400 per year, but that will only deliver these additional missiles after 2027 or later. For example the sole ammonium perchlorate supplier for every US solid rocket motor runs one plant in Utah, and the sole HMX/RDX source is a WWII facility in Tennessee…

The US has procured roughly 270 PAC-3 MSE ( the Patriots ) per year since 2015, but has diverted around 600 to Ukraine over four years. The exact remaining US stockpile is not known with the same precision as THAAD/SM-3, so they could not have more than 3000 before Epic Fury...

But it is known as I said above, Gulf allies burned through 600 to 800 or more PAC-3 MSE in the first 72 hours of Epic Fury alone from their own stocks. Since they have zero domestic production capacity, and will be competing with the US for the same Lockheed production line that only makes about 600 per year, Iran really has them by the balls.

By the way, the cost so far in munitions is 20 billion ( check references…).

Then on Intelligence...

Iran has 13 satellites of their own, and it is known to be receiving intelligence from the Russians. This data allows them to know exactly how many Patriots or THAAD were fired so far. They are also probably customers of MizarVision, a Chinese AI startup, that has been cataloguing every significant American military asset in the Middle East. Every base, every carrier strike group, every F-22 deployment, every THAAD battery, every Patriot missile position, tracked, labeled, analyzed, and posted publicly.

So...

Unless the US escalates to a Ground Invasion (most likely scenario…), or negotiates a deal with Iran, if Iran can keep their industrial production of missiles, or maybe move them far up and inside tunnels in its Northern Mountains, and...if the USA does not escalate to a ground invasion due to the political risks, they can actually win this war both from the political and strategic aspects, as incredible as that might seem.

Who is truly screwed are the Gulf countries, as their stocks of US missiles get progressively depleted… And they wont get a refill soon.

Russia strategic interests are in helping Iran, since it weakens the US and strengthens their hand in Ukraine.

What might make it worst for the Iranians is the Chinese view of this. I speculate they will prefer to help the US and its economy, by forcing the US to do a great commercial interesting deal for them, then using their strong leverage on Iran to come to an agreement.

Strategically, over the next four to six months: Russian wins, Iran wins (despite all the destruction), China wins, Israel loses, the US loses. Trump truly is the biggest loser...

"Are We Running Out of Missile Defense Interceptors?" - https://www.csis.org/events/are-we-running-out-missile-defen...

"‘Race of attrition’: US military’s finite interceptor stockpile is being tested" - https://www.defensenews.com/news/your-military/2026/03/06/ra...

"The Depleting Missile Defense Interceptor Inventory" - https://www.csis.org/analysis/depleting-missile-defense-inte...

"Over 5,000 Munitions Shot in the First 96 Hours" - https://www.fpri.org/article/2026/03/over-5000-munitions-sho...

"A Chinese AI Startup With 200 Employees Is Mapping Every US Military Asset in the Middle East — In Real Time" - https://breached.company/mizarvision-chinese-ai-satellite-us...

https://www.mizarvision.com/

aftbit3• 4 months ago

How does this guarantee a political and strategic win for Iran?

Iran was already teetering on the edge of being a failed state: socially, economically, environmentally, and agriculturally. Iran is expending expensive ballistic missiles to force those THAAD and Arrow shoot-downs. Yes, they're winning the shot exchange ratio, but their economy is orders of magnitude smaller than the US. Besides, unlike the Gulf states, the US and Israel are not just sitting around playing defense. They are systematically destroying substantial fractions of the Iranian war machine and have both threatened and attacked domestic and international energy production, the lifeblood of the Iranian economy.

The only true winner of this war, however it shakes out in the end, is Russia. All of the Middle Eastern powers aligned with the US are going to be desperate to rebuild their interceptor stockpiles and will surely get priority over Ukraine, likely for a very long time as the production rates are very low as you've pointed out. Plus, Russian gas and oil are worth a lot more than they were prior to this war, and are being allowed to trade more openly as well.

maxglute8• 4 months ago

Iran already bled enough high end regional interceptors, the strategic balance is if they can build enough moped shaheeds that can be assembled in garages to overwhelm whatever comes in theatre. And we know upper limit of US+co interceptor production for next 3-4 years. Economic size =/= productive capability. Ultimately Iran with survivable regional strike complex can existentially threaten gulf state adversaries who are all dependent on desalination while Iran, as shit as their water crisis is, is not. UAE, Qatar Saudi and Israel are like 70-90% desalination. They can threaten Iran economic lifeblood, Iran can literally end their lifeblood. Iran simply has massively more lethal/credible escalation dominance vs GCC. Iran already being failed state ironically allows them to escalate harder - they have much less economy to lose, vs GCC losing economy and biology.

Ultimately if Iran locks down Hormuz long term they can transit tax their way to prosperity, and if they can convince PRC to be enforcer of petro-yuan (big if), they'll basically get unlimited hardware to do so. Not that burning bridges with GCC is PRC first choice, but if Iran can lock down Hormuz, they have leverage to compel PRC to accept arrangement because it's worse than no Hormuz energy. The spoiler obviously is US who would rather toast GCC oil than lose petro dollar. Or Israel being nuke happy.

Havoc3• 4 months ago

They're not going to win. It's about extracting as much concessions

Remember the US attacked Iran, not other way round. Iran didn't start a war they thought they could win.

ifwinterco• 4 months ago

The democratisation (if that's the right word) of high quality satellite imagery is really something.

Of course top military powers will have even better images, but there are random Twitter users and YouTubers commissioning imagery of Russian tank bases and as long as there's no clouds on the day in question the quality is pretty good.

Things that move (ships) are still very hard to find and that's where the top powers still have a real advantage, but military bases, storage depots etc. are all impossible to hide in 2026. Even your local ragtag jihadist group can get coordinates for all your bases with a small amount of money and effort if they need them.

Making missiles that are accurate enough to take advantage of all the targeting data is still quite hard though

granoIacowboy• 4 months ago

Not necessarily disagreeing with your conclusions, but you aren’t factoring in other European or Korean interceptors the GC have been using. Israeli production. Fighters and other systems can be used for drone defense - lasers, AA guns, Manpads, EW, microwaves - Ukraine’s drone on drone defense and other solutions will be implemented asap.

The math is still brutal

Teever• 4 months ago

Great comment. I'm really concerned that the average American isn't taking this impending calamity seriously because they're completely unable to reason about a world where America doesn't have absolutely military supremacy due to decades of propaganda and the American identity being so tightly entwined with the American military mythos.

Any time that I've raised this issue of unsufficient stockpiles and poor preparadness for a major conflict for about a year now on HN and the response is pretty poor and my comments are often downvoted and/or ignored.[0][1][2][3]

There doesn't seem to be a way out of this without a substantial and undeniable US military loss that wakens people to the severely dysfunctional state of military stockpiles and planning, but with that said I'm highly skeptical that this incarnation of America can rise to the occasion like previous generations did in WW1 and WW2.

[0] https://news.ycombinator.com/item?id=42391816 [1] https://news.ycombinator.com/item?id=43693330 [2] https://news.ycombinator.com/item?id=44812177 [3] https://news.ycombinator.com/item?id=45054414

blueblisters• 4 months ago

Gaming this out for peer adversaries is mostly moot, right? The post-Cold War strategic balance has mostly hung on MAD. And Russia, in particular, has responded to any attempt at building missile shields with more capable missiles.

It's likely more relevant for asymmetric conflicts that involve conventional weapons, and would enable an otherwise less resourced adversary to become a near peer.

Dennis Bushnell from NASA presented this deck in 2001, and is quite prescient about UAVs and distributed warfare.

https://alachuacounty.us/Depts/epd/EPAC/Future%20Strategic%2...

CamperBob2• 4 months ago

Eh, he threw so much random stuff at the wall that some of it is bound to stick. An early slide in his presentation says there will be "no pixie dust," but that's 90% of what follows.

deepsun• 4 months ago

And that is the answer to Fermi paradox "why we don't see any other civilizations in the galaxy".

solatic3• 4 months ago

The math and economics on missile defense are broken.

If your adversary uses nuclear-tipped missiles: within hours if not days, you are virtually guaranteed to suffer impact. Congratulations, New York is under a mushroom cloud. Lose.

If your adversary doesn't use nuclear-tipped missiles, you have a war of attrition whereby the cost of interceptors is greatly more expensive than the cost of building the conventional missiles. Congratulations, you wrecked your economy, if you can even keep up production of interceptors for long enough. Lose.

The only winning moves are to either use ground troops to invade and dismantle your opponents' missiles to prevent that risk from being realized, or to play mutually-assured destruction games trying to convince the other side that you're just an insult away from doing it anyway. And a Western world that seems desperate to keep boots off the ground is not playing that winning move.

mikkupikku• 4 months ago

The "if only one nuke gets through, you lose and the whole thing is pointless" is completely wrong. Even if surrender were mandatory after one nuke, all the other intercepted nukes would be thousands if not millions of lives saved.

Brybry• 4 months ago

the cost of interceptors is greatly more expensive than the cost of building the conventional missiles

And the same thing is true with this comparison. The cost comparison is not interceptor vs conventional missile.

It's interceptor vs conventional missile + the damage the missile would have done.

Yes, you don't want to use Patriots to intercept Shaheds but that's an argument for using the right tool for the job. It's not an argument that the economics of interception are completely broken.

Ukraine has interceptors that are cheaper than Shaheds.

aftbit3• 4 months ago

Shot exchange is a huge problem, made even worse by the arrival of cheap drones. But you're implicitly assuming that the adversary is on roughly equal economic footing. If your defense budget is $800 billion and your adversary's defense budget is $8 billion, you can afford to spend 100x as much shooting down their missiles as they spend lofting them.

There's also a danger in projecting linearly from the beginning of a war, where invading forces both tend to use more expensive stand-off munitions and also have to deal with more aggressive missile launches. As the defender's own air defense system gets degraded, the invader can switch from expensive long range stand-off munitions to cheaper stand-in munitions (like glide bombs) launched from much shorter range. Additionally, the invader will be able to diminish the defender's ability to launch missile strikes in the first place, either by destroying the launchers, the missiles themselves, or their production, thus reducing the demand on expensive high-capability interceptors.

Drones and mines continue to offer asymmetric warfare options that are very hard to counter without a robust low side on the high-low mix. Ukraine are the world's leading experts in this currently, and hopefully are involved with US and Gulf forces to try to improve this shot exchange ratio.

I am assuming nobody is using nukes though. That completely changes the picture. One must always assume "(some of) the missiles will get through". Traditional MAD does not require boots on the ground - merely the assurance that if Iran gets one nuke through and hits New York, the USA will respond with 100+ nukes. The real question then is what the other "large" nuclear powers (Russia and China, primarily) will do in response to that.

solatic3• 4 months ago

Defense budget is an abstraction. At the end of the day, there are only so many factories with only so many raw inputs producing only so many interceptors per day. You cannot simply increase the defense budget in the event of a war of attrition and then attempt to outspend your enemy. And this is beside the political unpopularity of high defense budgets in peacetime, when they would need to be higher, to build the industrial capacity ahead of when it would be needed.

kurthr• 4 months ago

The losing move is using missile interceptors.

Whether it's high altitude drone swarms, terminally guided artillery munitions, hypersonic rail guns, or high energy laser defense, all are orders of magnitude cheaper than the interceptors and could be less than the cost of the (nuclear?) missile. It's true that generically defending against nukes is basically a fools errand, but if they're (also stupidly) limited to putting them on ICBMs with non-detonating fail safes, then it's probably economically doable and cheaper than the $10T forever war.

I'm sorry, the whole framing of this (OP) question/answer seems artificial and fundamentally silly.

chasd002• 4 months ago

i don't think complete invulnerability was ever the goal of missile defense. It was meant to be a countermeasure to something where before there was none. I'm actually surprised it works as well as it does. Back when these things were first being developed and tested the thought was intercepting nuclear armed ICBMs, they were supposed to be massively destabilizing with respect to MAD and could conceivably give a nation first strike advantage. First strike advantage means just bare minimum survival not that you never get hit at all. Fortunately, that never really materialized.

PowerElectronix• 4 months ago

Ground troops that can't advance due to a cheap nonstop drone and missile barrage is also not a solution as you are going to run out of troops before ypur enemy runs out of drones.

solatic3• 4 months ago

Ukraine is a poor example here because we've been poor allies to them. Drones are manufactured in factories that can be bombed, stockpiled in warehouses that can be bombed, transferred to the front lines in trucks that can be bombed. But Ukraine doesn't have the air force assets to achieve that. The Israelis do, and the amount of drones that have been launched at Israel has dropped considerably over the last three weeks.

Havoc3• 4 months ago

There is also a big real world experience element that is hard to account for mathematically.

There are stories of ukrainian operators expressing bewilderment and BCC countries sending 8x interceptors at millions a pop at a 20k shaheed. The world doesn't seem to have acclimatized to well...how the world works now.

There is a very fundamental disconnect at play here and I fear it'll get us all into trouble

mattmaroon2• 4 months ago

Well, it’s less about the value of the interceptor and more about the value of what the drones are heading for. If it’s a desalination plant that makes 20% of your freshwater, eight missiles are probably well worth it because a lot of people can die.

Middle Eastern countries have much more condensed critical infrastructure and economic targets than we do.

Iran has expected a war like this for decades and been continuously preparing, most of the other nations they have not.

Havoc3• 4 months ago

That logic right there is why the US is going to lose. That math only works in isolation

The Ukrainians don’t think about today’s tradeoff but also about tomorrows. They learned that when when a three day special operation turned into four years.

You have to match your best defenses against the best expected incoming attack- across time- even if it means taking a hit. Yes desalination plant included

The us doctrine of defend all the things all the time against everything has failed in light of modern drone warefare

egorfine3• 4 months ago

The world doesn't seem to have acclimatized to well...how the world works now

It has been observed that military bureaucracies will do everything in their power to ignore the fact that their experience is now obsolete and requires a complete refactoring.

This is why the countries were still not ready for Shaheds despite tens of thousands of them having been shot into Ukraine and despite enormous ukrainian experience and military know-how being readily available.

enaaem• 4 months ago

Yeah this is really bad news for Israel. America does not have the resolve for a major ground invasion, and Israel cannot intercept missiles indefinitely.

MoonWalk• 4 months ago

Whatever that means.

brcmthrowaway• 4 months ago

So this is what RAND corporation spends all day doing.

VerifiedReports• 4 months ago

What is that supposed to mean?

egorfine3• 4 months ago

developed [] algorithm that solves instances with 10,000 [] in under 7 minutes on a Macbook Pro [] The prior state-of-the-art timed out at 2 hours

Knowing how government IT procurement works, I'm afraid it's going to stay >2h for the foreseeable future even if the COTS solutions will bring this time down to a subsecond calculation.

verisimi• 4 months ago

The graphic shown has very '95 flavour.

treebeard901• 4 months ago

China, Iran and Russia can vastly out produce missle interceptors. Drones, hypersonics, etc.

They can also manufacture launchers faster and cheaper than they can be countered. $30k drone vs interceptor at millions.

The U.S. and Israel will not accept the current regime staying in power.

Neither side wants to stop the war. Israel, Europe, the U.S., gulf states and others in missile range of Iran will not want the current regime to remain in power.

What happens next? Full invasion? Regime change Iraq style??

Here is a highly probable outcome before next year. Iran continues breaking the Iron Dome and firing on "allied" targets and infrastructure. The U.S.refuses or cant sustain a full invasion (because it is a death trap).

What happens next? It is obvious Israel will use tactical nukes on Tehran and other targets in Iran. It is going to be their only option.

dgroshev3• 4 months ago

Not sure where the crucial SSPK number came from, given that the referenced link https://missilethreat.csis.org/system/gmd/ does not have neither the number nor data to calculate it. Even more importantly, using the test history too far back is incorrect, since the system was debugged and refined.

Also, a big omission in the post is NGI carrying multiple kill vehicles. Considering the relative cost of a launching system and a KKV, multiple KKVs flip the math quite significantly.

Missile defense is NP-complete

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