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Missile defense is NP-complete

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Re: Missile defense is NP-complete

#301

Post by lumost »

fpoling wrote: post #272
rdtsc wrote: post #237

Earlier quoted context omitted.

Now imagine for the same $10k cost making a cruise missile, instead. This is close to what a Shahed is -- the estimate is $20k-$50k / unit, so close enough. This is bonkers. Countries can now afford for the same cost * to make not a 10-20 mile range artillery shell, but a 1500 mile effective range cruise missile. * Defense costs are "fake" to a large degree. A lot of that is really corruption with money flowing from…

It is vastly more complicated to find targets at 1500 miles than at 20. So drones are effective at destroying big stationary civilian infrastructure and much less at long distance strikes at military targets. Russia's inability to destroy Ukrainian aviation is a good example. But then with solar and batteries civilian infrastructure becomes much more resilient against drone strikes.

At a certain distance, I'd contend all infrastructure is big and static. Our energy comes from large facilities, without these facilities continent scale infrastructure will grind to a halt at 1500 miles. Rail, power lines, warehouses, factories and trucks are all relatively static. It's not unreasonable to expend a Shahed type drone on a simple semi-truck parked overnight from nearly a continent away. There are only 3 million semi-trucks in the entire US, and I'd be shocked if the country could run without them.

Re: Missile defense is NP-complete

#302

Post by teleforce »

pjc50 wrote: post #183
teleforce wrote: post #144

Earlier quoted context omitted.

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".

There were significant civilian casualties right from the start of the war in Ukraine, and several massacred villages. Russian air defense shot down a civilian airliner mostly full of Dutch nationals and the response was just condemnation and tweaking the sanctions a bit.

My heartfelt sympathy to the MH17 victims and families, but the airplane was flying in the risky warzone. That does not discount the fact that it's an atrocious act by the Russian backed military.

However, to send missile to primary school killing hundreds of school girls on the very first day of the war, if intentionally is just pure evil.

Re: Missile defense is NP-complete

#303

Post by metaphor »

mrguyorama wrote: post #225
koakuma-chan wrote: post #206

Earlier quoted context omitted.

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

https://en.wikipedia.org/wiki/Advanced_Inertial_Reference_Sp... This is what we had to build in the 60s to allow a missile to know where it physically existed precisely enough to allow it to 50% of the time hit within a circle of ~50 meters. When you get to certain points in physics, certain energy regimes, you no longer are building machines or tools or something mass market. You are building artisan scientific inst…

> This is what we had to build in the 60s...

>> drift less than 1.5×10−5 °/h

Wow...just wow. Not a GNC engineer, but that drift spec strikes me as exceptionally good today, let alone the 60s.

EDIT:

> Even modern laser ring gyros do not even share a dinner table with the precision and accuracy of the above singular component of the Peacekeeper ICBMs, and that was a long time ago.

No kidding; full transparency, that was my basis of comparison.

Re: Missile defense is NP-complete

#304

Post by wat10000 »

david_pearce wrote: post #294
wat10000 wrote: post #217

Earlier quoted context omitted.

My assumption would be that the attacker builds missiles based on the defenses they want to defeat. If you have no defenses, maybe the defender builds 1,000 missiles. If you have 1,000 interceptors with 100% accuracy, then maybe the defender builds 2,000 missiles. This is why the superpowers mostly scrapped their ICBM defenses in the 70s. The technology worked fine. It's totally doable with 1970s technology if you're…

>However, the British were able to maintain the ability to defeat that system and destroy Moscow with a single submarine, all on their own What are you referring to here?

The missiles on the UK's nuclear missile submarines were fitted with decoys. One of the three warheads carried by each missile was replaced with a dispenser that would deploy 27 decoys. A single submarine carried 16 missiles, so it could launch 32 warheads and 400+ decoys at Moscow. The Moscow defenses had 100 interceptors, so it was pretty much guaranteed that at least one warhead would make it through.

More recently, they upgraded to newer missiles which could carry 8 warheads each, allowing them to overwhelm Moscow's defenses without decoys.

See: https://en.wikipedia.org/wiki/Chevaline

Re: Missile defense is NP-complete

#305

Post by falcor84 »

marcosdumay wrote: post #193
falcor84 wrote: post #80

Earlier quoted context omitted.

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…

> when part of their reasoning and authority is based on a divine mandate If you are atheist is becomes rational to surrender to the people that are invading your house and killing your friends at random?

Yes.

Absolutely.

If there are invaders who are killing everybody around me and telling me that they'll stop and generally let me be if I surrender and agree to live in a democracy, I expect that I'll be very inclined to accept. Maybe afterwards, if I see it's not working out, I may still consider guerrilla resistance down the line, but I don't see the benefit of fighting and most likely dying just for the sake of defiance, and to then allow any survivors a chance to continue in their resistance for another decade or so, until eventually they might be able to start rebuilding a nation from the rabble.

In what world is surrender, keeping our lives and infrastructure, not a more rational approach?

EDIT: To be clear, while I occasionally have pacifistic thoughts on pretty spring days, I'm not arguing for pacifism here - fighting is absolutely rational when you have a clear path to victory, but if you don't, then I think it's just an absolute waste of human lives.

Re: Missile defense is NP-complete

#306

Post by wat10000 »

bluGill wrote: post #289
wat10000 wrote: post #217

Earlier quoted context omitted.

My assumption would be that the attacker builds missiles based on the defenses they want to defeat. If you have no defenses, maybe the defender builds 1,000 missiles. If you have 1,000 interceptors with 100% accuracy, then maybe the defender builds 2,000 missiles. This is why the superpowers mostly scrapped their ICBM defenses in the 70s. The technology worked fine. It's totally doable with 1970s technology if you're…

That worked in 1970 because there were exactly two players who had incentive to not spend all the money so they agreed to reduce the total ICBMs instead. In the current world there are too many actors - it won't work, they can make thousands of missles. Ukraine has already proven you don't get to control when you are attacked. Thus the only option today is cost reduce defense and produce enough to intercept several t…

It doesn't matter if it's the only option if it's not possible to do it.

Maybe it is possible. It does seem like it may be possible to defend against cheap drones with cheaper systems. Use lasers or good old-fashioned projectile guns instead of interceptor missiles.

For defending against proper missiles, I don't see how it's possible with any near-future tech. Guns and lasers don't work. You have to use a missile and it's going to have a cost similar to the cost of what you're shooting down. Peer enemies will be able to out-build you and many missiles will get through your defenses.

Shooting some down is better than shooting none down, but your enemy won't ignore your defensive systems. Shooting down 1,000 and having 1,000 get through is not better than shooting down 0 and having 1,000 get through. If building defenses just provokes the other side to build more offense, it's not worth it. If they're going to build the same amount of offense either way, then it might make sense to build up defenses.

Here's something to consider. The US has interceptors capable of shooting down ICBMs and with enough range to protect the whole continental US. There are currently 44 such interceptors. They cost about $75 million each. Standard procedure is to shoot four interceptors at an incoming missile to increase the likelihood of a kill, so that's about $300 million per incoming missile you want to counter. That's very much worth the cost if it prevents a nuclear warhead from reaching its target.

Russia and China together have maybe 700 ICBMs if we take a high estimate. For $210 billion, we could have enough interceptors to shoot down almost all of them. Round it up to $300 billion to account for all the infrastructure they'd need. That's a bargain compared to saving hundreds of American cities. So the question is: should we do it? So far, the American government has said "no." I agree with them, despite it being a bargain. Do you?

Re: Missile defense is NP-complete

#307

Post by maxglute »

aftbit wrote: post #239
inaros wrote: post #165

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 w…

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,…

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.

Re: Missile defense is NP-complete

#308

Post by dgoldstein0 »

rdtsc wrote: post #237
Cpoll wrote: post #229

Earlier quoted context omitted.

> US makes ~50k artillery shells a month at a cost of about 10k per shell. 50000 * 10000 * 12 is 6B/year. I was surprised, but I suppose that passes the smell test for a ~1T/year defense budget.

Now imagine for the same $10k cost making a cruise missile, instead. This is close to what a Shahed is -- the estimate is $20k-$50k / unit, so close enough. This is bonkers. Countries can now afford for the same cost * to make not a 10-20 mile range artillery shell, but a 1500 mile effective range cruise missile. * Defense costs are "fake" to a large degree. A lot of that is really corruption with money flowing from…

1500 mile range is questionable in practice I've read - drones require remote control for maximal value and that's a capability that may not extend nearly as far as the paper range of the drones

Re: Missile defense is NP-complete

#309

Post by rdtsc »

dgoldstein0 wrote: post #308
rdtsc wrote: post #237

Earlier quoted context omitted.

Now imagine for the same $10k cost making a cruise missile, instead. This is close to what a Shahed is -- the estimate is $20k-$50k / unit, so close enough. This is bonkers. Countries can now afford for the same cost * to make not a 10-20 mile range artillery shell, but a 1500 mile effective range cruise missile. * Defense costs are "fake" to a large degree. A lot of that is really corruption with money flowing from…

1500 mile range is questionable in practice I've read - drones require remote control for maximal value and that's a capability that may not extend nearly as far as the paper range of the drones

They can’t be used for moving targets but for infrastructure they can be effective. At the cost of only a few artillery shells send 10 and maybe 3 will hit.

Another advantage is because of simplicity and cost it allows quick iteration and adaptability. Use honeycomb patterns to lower radar signatures, use specialized antijamming gps/glonass antennas. Engine is too slow? Add a small turbojet. Color too light and visible at night? Paint it gray, etc. That can happen at the speed of weeks and months. Try doing that with Tomahawks, artillery pieces or HIMARS.

Re: Missile defense is NP-complete

#310

Post by [deleted] »

elzbardico wrote: post #275
srean wrote: post #161

Earlier quoted context omitted.

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…

Technically those are ballistic missiles with Multiple Independent Re-Entry vehicles not cluster munitions.

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