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Missile defense is NP-complete

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Re: Missile defense is NP-complete

#171

Post by reillyse »

srean wrote: post #161
roysting wrote: post #100

Earlier quoted context omitted.

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 frau…

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…

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.

Re: Missile defense is NP-complete

#172

Post by pc86 »

iso1631 wrote: post #129
energy123 wrote: post #121

Earlier quoted context omitted.

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 att…

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)

If "I want this land" is a legitimate reason to initiate a war then basically anything is a legitimate reason.

Re: Missile defense is NP-complete

#173

Post by owenmarshall »

jandrewrogers wrote: post #149
owenmarshall wrote: post #109

Earlier quoted context omitted.

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 Russ…

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 syst…

> 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-...

Re: Missile defense is NP-complete

#174

Post by pc86 »

wat10000 wrote: post #78
bluGill wrote: post #28

Earlier quoted context omitted.

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, eve…

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…

> 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.

Re: Missile defense is NP-complete

#175

Post by pc86 »

maratc wrote: post #141
owenmarshall wrote: post #69

Earlier quoted context omitted.

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; o…

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_D…

I don't know the economic numbers off the top of my head but I have to imagine it's hard to find Israelis who think they're spending too much money on rocket interceptors.

Re: Missile defense is NP-complete

#176

Post by elfly »

ceejayoz wrote: post #99
energy123 wrote: post #56

Earlier quoted context omitted.

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.

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.

USA won't injure or kill 1 in 25 of young adults in the Iran war, unless somehow Iran does have a nuke and wants to use it, come on.

Re: Missile defense is NP-complete

#177

Post by ceejayoz »

elfly wrote: post #176
ceejayoz wrote: post #99

Earlier quoted context omitted.

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.

USA won't injure or kill 1 in 25 of young adults in the Iran war, unless somehow Iran does have a nuke and wants to use it, come on.

Raw manpower is hardly the only aspect of war.

Especially in modern war.

Running out of fancy equipment, for example, causes quite a few problems if your opponent hasn't. Like interceptor missiles.

Re: Missile defense is NP-complete

#178

Post by elfly »

iso1631 wrote: post #129
energy123 wrote: post #121

Earlier quoted context omitted.

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 att…

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)

Ah yes, Russia, the famously territory starved country.

Re: Missile defense is NP-complete

#179

Post by pjc50 »

9cb14c1ec0 wrote: post #102
nerfbatplz wrote: post #75

Earlier quoted context omitted.

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.

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.

In a direct conflict with China, the ICBM exchange would destroy the F35s on the ground.

Re: Missile defense is NP-complete

#180

Post by pc86 »

wat10000 wrote: post #140
maratc wrote: post #115

Earlier quoted context omitted.

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.

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 could…

Yes, it's complicated. There's almost 1,000 generals and officers spread across the US military. They (and the tens of thousands of people directly supporting them) spend a lot of time on these things.

Sometimes "draw the rest of the owl" makes sense when you've got 20,000 people actively drawing owls all day every day.

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