Missile Defense Is NP-Complete
157 points by O3marchnative 3 hours ago | 168 comments
  • dboreham 3 hours ago |
    It's been known since the 1960s that effective anti ballistic missile defense is impossible.
    • trollbridge 3 hours ago |
      A lot of things involving rockets and putting things in space have changed since the 1960s.
      • skywhopper 3 hours ago |
        Have they, really?

        * Small rockets can now land themselves.

        Anything else?

        • sumtechguy 3 hours ago |
          Computer guidance? Better materials? Better telemetry?
          • pwndByDeath an hour ago |
            Still short amount of time to make a decision based on very messy data
      • BoredPositron 3 hours ago |
        Observability has changed in most other ways we have regressed.
      • XorNot 2 hours 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 3 hours 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.

      • hedora an hour 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 3 hours 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.
  • delichon 3 hours 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.
    • busterarm 3 hours ago |
      Careful. Preemption takes many forms, some of them many would find unpalatable.
      • gos9 3 hours ago |
        Unpalatable preemption is generally better than reentry vehicles coming down your chimney.
        • phkahler 2 hours ago |
          The problem there is you can't prove anything would have come down the chimney if the preemption is successful, so people will still be unhappy.
          • busterarm 2 hours ago |
            I agree, but some of them are more obvious.

            Like not giving 100 billion dollars to someone who actively wants to kill you.

        • wat10000 2 hours ago |
          A thought experiment: would the world be a better place if the US had preemptively attacked the USSR in the 50s or early 60s when it was possible to do without more than “get[ting] our hair mussed” as General Turgidson put it?
      • XorNot 2 hours 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.
    • heyitsmedotjayb 3 hours ago |
      Preemption is a propaganda lie.
      • hedora an hour 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 2 hours 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.

    • jmyeet 2 hours 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-...

    • jandrewrogers an hour 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.

  • heyitsmedotjayb 3 hours 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 3 hours ago |
      > And then again how they change when all your L band radars are destroyed...

      Connection reset by Yugoslavs with microwave ovens

  • jsw97 3 hours 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 3 hours 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.
    • testaccount28 3 hours ago |
      there is a benefit as well, though, as it makes your threats credible.
    • SegfaultSeagull 3 hours ago |
      Or perhaps they will learn they are outmatched, lack the resources and technological capabilities to compete, and deterrence will have been established.
      • biker142541 3 hours ago |
        History would suggest otherwise; rarely is this ever the case.
        • marcosdumay 2 hours ago |
          You seem to be implying that there is a long history of countries starting wars against the USA?
          • gzread 2 hours ago |
            More like the USA starting wars against countries, and those countries not immediately surrendering, to which the USA is shocked.
            • falcor84 2 hours ago |
              I think that there's a more general issue here with the US and the West in general having a mindset built up on playing Risk and Civ, which considers the foreign country as a whole as their opponent, whereas in practice, the adversaries are a multitude of individuals, for almost none of whom a surrender is the rational choice, especially (as sibling comments pointed out) when part of their reasoning and authority is based on a divine mandate.
              • testaccount28 an hour ago |
                to be clear: your claim is that the us military is misinformed because key constituents have played too many board games?

                does hearing it back like that make it seem absurd to you as well?

                • falcor84 30 minutes ago |
                  Well, yes (except that Civ isn't a board game). And no, it doesn't make it seem absurd to me.

                  My argument is that Western strategic thought (with games being a codification thereof, rather than the source of) generally considers countries as mostly atomic actors that can be defeated - the history of European warfare being filled with "gentlemanly" surrenders followed up by peace treaties, with guerrilla warfare being a very rare exception.

                  On the other side, the reality in the East is that a state's collapse doesn't end the conflict, but just prolongs it. The army doesn't surrender, it goes home with its weapons and reconstitutes as insurgents. I can't actually think of a single proper surrender of an Eastern country ever, except for Japan in 1945.

                  • dragonwriter 20 minutes ago |
                    > Well, yes (except that Civ isn't a board game).

                    It is actually several physical board games, the oldest of which is older than (and unrelated to) the computer game [0], as well as being a series of computer games that are basically digital board games.

                    [0] Well, except for the computer game based on it and its expansion, which, because of the other computer game, had the long-winded title "Avalon Hill's Advanced Civilization".

        • quietbritishjim 2 hours ago |
          History doesn't necessarily make it clear when a war might have started but didn't because of some specific factor. Mainly you see the wars that did happen. (It has a strong survivorship bias in the sense that a war "survived" history if it went ahead for real rather than being considered and decided against.)
      • pjc50 2 hours 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.
        • deburo 2 hours ago |
          That's not what deterrence means. From google: the action of discouraging an action or event through instilling doubt or fear of the consequences.

          It's meant to avoid conflict altogether, say with China and Taiwan.

      • varispeed 2 hours ago |
        You miss the fact that many adversaries will not act rationally.
        • baxtr 2 hours ago |
          Especially when they're optimizing for afterlife.
        • iso1631 an hour ago |
          Yes, if it was acting rationally the US Would not have spent billions trying to blow up an 80 year old man while massively increasing the price of oil and fertiliser globally leading to economic instability

          But the US has not acted rationally. It hasn't since January 2021.

          • varispeed 37 minutes ago |
            There could be a rational explanation if you assume US administration is compromised by Russia and Ayatollah's son wanted him out to assume power. One phone call to Putin, Putin's one phone call to Krasnov and everyone is happy. Son gets the power, Russia gets sanctions lifted, higher oil price, US and allies spend kit that cannot be now sold to Ukraine, Krasnov gets to play the stock market. Win-win-win.
      • dlisboa 2 hours 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.

      • nerfbatplz 2 hours 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.
        • 9cb14c1ec0 an hour ago |
          To be clear, that F35 was being incredibly careless, flying low in broad daylight. All the stealth features of an aircraft are useless if you can look at it with your own eyes. In any conflict with China, F35s would not be flown that way.
          • nerfbatplz an hour ago |
            To be clear, Trump announced that the US had destroyed Iran's air defenses, missiles and missile launch capabilities. Trump also said that the US enjoyed air supremacy over Iran and were flying when and where they wished.

            Maybe one of these days we'll see a B-52 take off with JDAMs and not JASSMs but probably not, kind of scary to try and drop gravity bombs on a country that your stealth fighters can't fly over.

            https://www.youtube.com/watch?v=tohttYlvFvU

          • iso1631 an hour ago |
            You're holding it wrong?

            How many cheap-ass drones could you buy for the cost of one F35. 100k? A million?

    • 1234letshaveatw 3 hours 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
      • lejalv 2 hours ago |
        Stakes for whom?

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

        • keybored 2 hours ago |
          “Iranian kids may die... but that’s a prize I’m willing to pay.”
          • 1234letshaveatw an hour ago |
            "I much prefer nuclear conflict"
            • keybored an hour ago |
              Propose a nuclear free zone in the Middle East, propose a global nuclear free zone, propose to cooperate with other nuclear powers to disarm.

              But that’s apparently not the real concern at all.

        • 1234letshaveatw an hour ago |
          The USA
        • 1234letshaveatw an hour ago |
          How many protesters were killed leading up to it?
          • keybored 28 minutes ago |
            How does bombing a school help protesters?
        • teleforce an hour ago |
          Imagine the NATO reaction if on the very first day of Russo-Ukrainian war offensive is by Russia performing missiles bombing murdering 100 kids studying in Ukraine primary school.

          Trump candid reaction to the Iranian school incident when asked by reporter was "I can live with that".

    • myrmidon 2 hours 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 2 hours ago |
        "Data moats" are a problem for military tech, too, I guess.
        • btown 2 hours ago |
          One very interesting instance of the "military data moat" is Ukraine's annotated database of drone footage, perhaps the first of its scale from live engagements [0]:

          > They can now draw on an enormous pool of real warfare information. Last year alone, Ukrainian drones recorded around 820,000 verified strikes against Russian targets... Meanwhile, the country’s Avengers AI platform detects upwards of 12,000 enemy targets every week. Developers can now access these sources and the data that they gather to train their systems on the movements of a real Russian turtle tank or a camouflaged Lancet launcher.

          > “Ukraine currently possesses a unique body of battlefield data unmatched anywhere in the world,” recently appointed Defence Minister Mykhailo Fedorov said in a statement. “This includes millions of annotated frames collected during tens of thousands of combat drone missions.”

          With the latency and offline constraints of battlefield technology, smaller models, trained with better data, may prove to have a significant edge. But it's still early days on how data like this might prove advantageous in other environments.

          [0] https://resiliencemedia.co/how-ukraine-is-transforming-its-b... (unconfirmed source, this is not an endorsement)

      • dlisboa 2 hours 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.

        • icegreentea2 2 hours ago |
          Air defenses do not need to be 100% effective to be... effective.

          Russia cannot keep Ukraine from targeting their oil infrastructure, yet here Russia is, still fighting on. Ukraine cannot prevent Russia from targeting their energy infrastructure or apartment buildings, yet here they are, still fighting on.

          If we're talking about strategic/civil air defense, then you must figure out what's tolerable to your population (and how to increase and maintain that tolerance), and then figure out all the means to reduce the incoming attacks to below that tolerance. That must include the full spectrum of offensive, counter offensive, defensive, and informational options.

          • energy123 an hour ago |
            In the Ukraine-Russia war, air defense is used to deny air superiority to the enemy. Just a few days ago, Ukraine blew up Russia's helicopters in the air with drones. It's not the successful hits that matter, it's the capabilities that you deny by posing that credible threat.
      • energy123 2 hours 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.

        • ceejayoz an hour ago |
          Except this looks likely to exhaust the US/Israel alliance, if it continues long, leaving China in the "US in/after WWII" spot in the analogy.
      • roysting an hour 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.

        • srean 28 minutes ago |
          I agree that a barrage of maneuvering missiles can be neigh impossible to defend against.

          Regarding these cluster munitions though, other than very densely populated areas, do they inflict much damage ? Are they more powerful than a grenade, say ?

          It's going to devastating to soft tissue surely, and pierce through ordinary sheet metal, but normal concrete walls might offer sufficient protection. Unless, of course, it punches through the ceiling by virtue of sheer kinetic energy.

          BTW I have no expertise in these matters, so corrections would be very welcome. I also recognize that I am commenting about something from the comfort and of being out of range and this discussion can be very distressing.

          • reillyse 12 minutes ago |
            Instead of a cluster of grenades think many drones, the numbers start looking pretty bad when you have 100s of drones rather than a couple of missiles.
      • maxglute 35 minutes 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?

    • p00dles 2 hours ago |
      who is our/us?
    • renewiltord 2 hours 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 2 hours 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 2 hours 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.
      • maratc 2 hours 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.

        • mamonster an hour ago |
          >The damage these inflict on Israel is not unsustainable, and they don't do much to create deterrence.

          Has there been a study on this? What is the GDP loss of having however many Israelis go to bunkers due to incoming ballistics instead of working ?

          If a trash cluster missile that costs 100k USD to build causes 1mio USD worth of GDP to not be produced (numbers completely made up) then it's very worth it.

          • maratc an hour ago |
            No idea about studies or GDP; just observing that the losses inflicted by Iran on Israel in June 2025 did nothing to deter Israel from going on offence again eight months later.
    • baxtr 2 hours 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.

    • jmyeet 2 hours 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...

      • jandrewrogers 2 hours ago |
        > Iran destroyed a bunch of them

        If by "a bunch" you mean one.

    • EthanHeilman an hour 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.

    • simonsarris an hour 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.

  • u_sama 3 hours ago |
    Great nerd title, the maths made me nostalgic as I haven't seen a Sigma/Pi in a few years
  • owenmarshall 3 hours 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...

    • jvanderbot 2 hours 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 2 hours 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.
        • jvanderbot 2 hours ago |
          No, what I said is not wrong just because there exists other things to intercept, that just changes the ratio.

          You still have to consider whether it's worth it to spend a patriot missile to intercept a drone, vs letting the drone hit, say, a billion dollar radar installation or a dozen troops.

          On the manufacturing side, nobody said that all drones are intercepted with patriots. You have to look at the avg cost to intercept vs the average cost to attack, and if the ratio of those avg costs (across all attack/interceptions) is, say 100:1, and the combined GDP of the defending nations vs Iran is 1000:1, then what is the problem?

          There are lower cost ways to intercept already on the market and being rolled out. See for example: https://www.defensenews.com/global/europe/2025/09/11/uk-to-p...

          This whole "cost analysis of patriot vs drone" examines the worst case scenario at a fixed point in time and ignores layered defenses, the effect of combined GDP, learning, diminishing capabilities of attackers, and improvements by defenders.

          • lejalv 2 hours ago |
            But your analysis should also include what fraction of GDP diverted to arms (or what increase in gas price) is acceptable on either side.
          • wat10000 2 hours ago |
            For one thing, the entire world economy is not even close to 1000x Iran’s.
            • hedora an hour ago |
              $1M / $30 (patriot cost / drone cost) is only 33x. The US economy is about 31x larger than Iran's. So, to first order approximation, we could build enough patriots to sustainably stop their drones.

              However, we haven't converted our economy to just producing Patriots. We can only produce 600 / year. Drone production rates are orders of magnitude higher than that.

              As for second order effects, the interception probabilities are less than one, so in this world where we're producing a million patriots per year, tens of thousands of drones (at minimum) are hitting their targets. On top of that, the offensive drones are more easily transported + retargeted, so the patriots would need to be stationed pretty much everywhere, and their adversary chooses where the attacks actually happen.

              The only winning move is not to play.

        • jandrewrogers an hour ago |
          They aren't using Patriots on Shahed drones. There are much cheaper purpose-built systems for that. While not practical everywhere, helicopter gun systems have proven effective in both the Middle East and Ukraine.

          APKWS is quite popular and those cost less than the drones. A single fighter jet can carry 40. The Europeans are developing equivalent systems.

          While not widely deployed yet, the US has operational laser-based anti-drone systems that have been shooting down Shahed class drone for a couple years now.

          Ballistic missiles are more costly to deal with but ballistic missiles also cost much more.

      • orwin 2 hours 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.

        • DoctorOetker an hour ago |
          > 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.

          Not to confuse my prediction from prescription, but what prevents all the neighboring (direct or indirect over a sea) nation states from deciding to divide Iran like Germany was during the cold war? Thats not an independent Balochistan, at some point they will want reparations for all the damage, terrorism and intimidation they have incurred from Iran...

          At some point the people in Iran will have to be forced to teach their innocent children the equivalent of the Nuremberg trials: there is no excuse in order to stop thinking, just following orders is not a valid legal defense.

          Every population has the moral responsibility to keep the local aspiring autocrats in check, because if they don't and external power deconstructs the regime, the onus will be on the population!

    • bluGill 2 hours 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.

      • ceejayoz 2 hours 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.

        • bluGill 2 hours ago |
          That is a trade off that hopefully you never need to consider, but it is a valid concern that does come up in the real world.
          • hedora 2 hours ago |
            It's not a hypothetical:

            Trump started blaming Biden for the US's interceptor shortage two days into the war. Third-party military analysts say there's a high probability Iran's drone stockpile will outlast the US's first-tier interceptor stockpile.

            The first-order math checks out: At the beginning of the war, we (and allies) were using 800 x $1M patriot missiles per day. The global production capacity for patriots is 600 per year, so there's no way we've have been able to maintain that cadence now that we're in week 4 of the war (the patriot program has not existed for enough decades). Now we see things like successful strikes on Israel's nuclear complex.

            If the math isn't good enough, note that Trump backed down over the weekend, after Iran reiterated that they'd target civilian infrastructure if the US did so first. If we still had adequate interceptor capabilities, calling his bluff would not have worked.

      • wat10000 2 hours 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.

        • pc86 3 minutes ago |
          > 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?

          I mean the assumption is that if the first missile hit the building, the second missile would have been fired at something else, right? Still seems worth it at face value especially if there's enough time between the two missiles that there aren't people in the building anymore.

    • maratc 2 hours 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.
      • owenmarshall 2 hours 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.

        • maratc an hour ago |
          In theory; in practice however, there's been rocket fire from Gaza towards Israel where the offence was literally a metallic tube with a bit of TNT at a cost of about $800 per rocket [0] while the defence was $100,000+ per interceptor [1]. This has been going on for years, and as far as I'm aware there was no depletion observed.

          [0] https://en.wikipedia.org/wiki/Qassam_rocket [1] https://en.wikipedia.org/wiki/Iron_Dome

      • wat10000 2 hours 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.
        • maratc an hour ago |
          Not if you (a) destroy their production capacity while they don't destroy yours; (b) you destroy their stockpiles while they don't destroy yours; and (c) you've found a bottleneck on their side (launchers) and destroy it while they fail to inflict the same damage on you.
          • wat10000 an hour ago |
            That's true, but feels very much like "draw the rest of the owl." And even if you can do it, you'd have to do it against any country that starts to build this capacity that you think might somebody potentially use it against you, even if they aren't currently, unless you're confident that you can destroy their launchers and stockpiles so quickly that they can't be used in any significant number. (And if the USA couldn't manage to do that to Iran....)
    • keybored 2 hours ago |
      Sobering how asymmetric Iran’s attacks on Israel are after Israel attacked Iran.
    • jonaslanglotz 2 hours 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.

    • hedora 2 hours 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.

      • owenmarshall an hour 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)".

        • jandrewrogers 41 minutes ago |
          This betrays your ignorance of drone defense tech.

          The US had APKWS (anti-drone guided missiles) operational in the 2010s and these have been widely deployed. They are effective and cost less than a Shahed. These are just mods of an existing dirt-cheap rocket for which the US has an effectively unlimited supply. The Europeans have similar systems under development.

          The US has deployed high-power anti-drone laser systems for a few years now with several operational kills. These are still new but are expected to replace CIWS. It can kill a drone for the cost of a Starbucks coffee and has a virtually unlimited magazine.

          US pioneered military drones and defenses decades before the Ukraine/Russia war. There are many operational lessons to be learned from that war but both sides are using drone defense tech that is considerably less sophisticated than what the US has available.

          • owenmarshall 8 minutes ago |
            > The US had APKWS (anti-drone guided missiles) operational in the 2010s and these have been widely deployed

            ... on 4th/5th gen fighters that cost tens of thousands per flight hour[0] based on current evidence of deployment. We're still killing mosquitoes with hand grenades.

            Iron Beam/the US systems are certainly interesting, but haven't been scaled up to meaningful deployments yet.

            Meanwhile, those "considerably less sophisticated" systems were fielded in exercises by the Ukranians against NATO doctrine and won handily[1].

            [0] https://www.defenseone.com/defense-systems/2026/03/fighter-j...

            [1] https://www.wsj.com/opinion/nato-has-seen-the-future-and-is-...

      • pc86 an hour 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.

        • dlisboa 37 minutes ago |
          A trillion seems large but it's not that absurd. The drone that shut down 17% of Qatar's LNG capacity is said to have caused 20 billion USD worth of annual lost revenue. They said it'll take up to 5 years to rebuild so that could be 100 billion USD in lost revenue, plus whatever it costs to do the rebuild.

          A trillion dollars worth of damage seems possible if spread over some years for some countries in the Gulf where shutting down a desalination plant would cause depopulation.

    • energy123 2 hours 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.
      • hedora an hour 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).

        • energy123 an hour ago |
          It's heavily dependent on geography. Iran is geographically "lucky" it's positioned near the Strait of Hormuz and near the oil facilities of multiple Gulf states, allowing it to exert extreme asymmetric pressure through a small amount of drones etc. Most states can't replicate that luck. Good luck to South Africa if they ever decide to wage a similar war. Strategic depth also largely nullifies the role of one-way attack drones in combat, but it doesn't nullify the role of fighters and bombers who can exploit that range. I'm not discounting drones, they're highly important in many geographies, as Ukraine is showing, but I don't buy into this conventional wisdom online that they're the pinnacle in every situation.
          • iso1631 an hour ago |
            It's America that's waging this war, having attacked Iran for no reason the world can see

            It's somewhat similar to Russia waging a war in Ukraine, although I can see some reasons for Russia to attack Ukraine (mainly territory)

            • pc86 11 minutes ago |
              If "I want this land" is a legitimate reason to initiate a war then basically anything is a legitimate reason.
          • dlisboa an hour ago |
            Israel is similiarly lucky that it is surrounded by neighbors with US bases that can intercept missiles and drones before they get to it. All of its more competent enemies are very far away. In a different scenario there'd be no motivation for a country like Iraq or Jordan to help.

            They can afford to try to destroy Iran's offensive capabilities because in-between countries allow their airspace to be used.

            Wars are usually between neighbors. If a neighbor has a huge stockpile of drones they can launch a first salvo that'll overwhelm whatever defensive capabilities the other country has before they even get to the point of destroying launchers/manufacturing.

            Threats of massive drones strikes are the closest deterrent a country can get to nuclear weapons without developing nuclear weapons. If Iran had 5 million drones instead of 50 thousand this war wouldn't even be happening.

          • hedora 26 minutes ago |
            Russia is already shipping containers full of Iranian drones to the Ukrainian front. It doesn't take much imagination to see how geographic location is going to matter less and less as technology improves.
  • srean 3 hours 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

  • quotemstr 2 hours 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.

    • myrmidon 2 hours 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 2 hours 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
        • hedora 40 minutes ago |
          They are, but only have a range of 1.2 miles in earth's atmosphere. Since they're on the ground, and presumably near the target (not the launcher), that means they're aimed at the warhead just before it hits the ground.

          I looked up the numbers, and, interestingly, ICBMs have to slow down before they hit their target. In the midrange flight, they travel at 15,000 mph, but at re-entry the warheads are only traveling at 1900 mph, or 0.58 miles per second.

          So, in the best case (the warhead is headed to the laser), the laser only gets 2.5 seconds of dwell time to intercept it. This rapidly decreases as the distance from the laser to the target increases (to 0 seconds of dwell time at 1.2 miles). Also, if the ICBM fires multiple warheads, or chaff, then you'd need to scale up the number of lasers or scale down the dwell time linearly, assuming they're all conveniently aimed within a small fraction of a mile of the laser (again, I'm assuming best-case).

          Current direct energy weapons have only been demoed against UAVs, probably for this reason.

          edit: my math is completely wrong: Modern nukes are optimally detonated at about 5000 ft above ground level. So, you get about 0.33 seconds of dwell time, assuming the attacker doesn't just set the warhead to detonate at a non-optimal (but still devastating) 1.2 mile altitude.

          https://remm.hhs.gov/zones_nucleardetonation.htm

    • OrangePilled an hour 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/

      • hedora 33 minutes 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 2 hours 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
  • energy123 2 hours 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 2 hours ago |
      The steady state would look like a sinusoidal signal. This is more of a cycle than a hill climbing thing.
      • energy123 2 hours 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%?
    • adampunk 2 hours 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.

      • energy123 2 hours 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).
        • adampunk an hour ago |
          Well there the cost plays a part! It’s not independent. If I can build 1000 missiles for every 1 interceptor, the probability of interception hardly matters.

          This actually was why we planned to put lasers in space: the economics of one nuclear-pumped laser reflected through Unobtanium were better than any other interceptor. And even that if the effect worked (it didn’t, they could not prove lasing and fired an engineer who blew the whistle on that), the system could be defeated by a staggered salvo.

        • hedora an hour ago |
          OK, assume infinite resources, but the attacker only has one missile, and the defender only has one interceptor.

          Optimal strategy for the attacker: Figure out how fast the interceptor can reach your missile, and have it split into a dozen warheads on different trajectories a mile before that. Include the blast radius of the interceptor in the calculation in case the defender decides to set of high-altitude nukes to defend itself against your missile.

          The non-proliferation treaties we just pulled out of banned multi-warhead ICBMs decades ago because there's no feasible counter-move. That's bad for the missile business.

          Back in reality, the attacker just builds 100,000 conventional drones, and 1 identical looking one with a nuke in it. Eventually, the defender runs out of interceptors, so the intercept probability trends to 0. At that point, the attacker sends the nuke without varying the behavior of the conventional drones.

  • jmyeet 2 hours 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.

    • sgtsteaks 2 hours 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.

  • captainswirly 2 hours ago |
    This is rocket defense, not missile defense.

    Pretty much nothing can stop those ICBMs - those aren't rockets.

    If you dig deeper than mainstream news - Iran is lighting Israel up with those ICBMs, but they don't use them too often.

    • nerfbatplz 2 hours ago |
      Technically Iran fires SRBMs and MRBMs not ICBMs. They intentionally gimp their missiles to avoid advertising ICBM range as a way of placating Europe.
      • captainswirly 2 hours ago |
        Cope harder. I saw the videos that Israel tried to ban.

        Whatever you want to call them, they are "hypersonic" traveling over 15k mph.

        They definitely look fast too in the videos where they smash into Israeli housing destroying everything in an instant.

        • Maken 39 minutes ago |
          ICBM means the missile is able to be launched into other continent (more than 5K kilometers in range), not about its effective warhead. Iranian missiles are fast and efficient, but their effective range is essentially being able to target Israel and the Gulf States, which means they are not ICBMs. Also, the one country in the Middle East who does have ICBM missiles and can target Europe is Israel, not Iran.
  • vaporwario 2 hours 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-chan 2 hours ago |
    Why does a ground based interceptor cost $75M? High idiot index?
    • hedora an hour ago |
      $1M, but we can only make 600 / year, globally.
      • koakuma-chan an hour ago |
        From the article,

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

        • hedora 30 minutes ago |
          I'm quoting the missile cost. I think they're quoting the launchers + a few missiles.

          (Also, lower bounding the cost improves the argument that they're too expensive to be practical.)

  • fisherwoman 2 hours 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.

  • sgtsteaks 2 hours ago |
    What are you gonna do when Iran destroys the missile defense system itself, oops already happened
  • contravariant an hour 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.

  • maxglute an hour 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.

    • Voultapher an hour 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...

      • gpderetta an hour 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.

      • maxglute an hour 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.
      • consumer451 39 minutes ago |
        Lasers are not "all weather" weapons as far as I am aware. Clouds, snow, fog, and rain all degrade their performance greatly.
        • O3marchnative 28 minutes ago |
          The recently announced "Golden Dome" project intends to get around this issue by putting a vast constellation of satellites into orbit. Each satellite would likely need a serious source of power in order to use its laser. Assuming that's just an engineering problem, then the issue becomes coverage. That is, depending on the adversary's capabilities, you'd need an absolutely massive constellation in orbit [0].

          [0] https://en.wikipedia.org/wiki/Golden_Dome_(missile_defense_s...

          • consumer451 26 minutes ago |
            This is such an insane concept of a plan, and I don't mean that in a good way.

            For one thing, it can do little to nothing about low flying nuclear tipped cruise missiles, especially in less than ideal weather.

      • apt-apt-apt-apt 14 minutes ago |
        Try that on my spinning, mirror-coated missile!
  • jcul an hour 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.

  • EGreg an hour ago |
    What happened to Iron Beam / lasers and those vaunted "space lasers" dubbed "star wars"?
    • hedora an hour 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

      • EGreg 21 minutes 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.

    • jandrewrogers an hour 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 an hour 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.
  • OrangePilled 31 minutes 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 26 minutes 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/