What capabilities does the US, NATO, or Russia have to take out incoming nukes?

Factual Questions
1

In an all-out nuclear exchange with the Soviet Union (USSR), I was taught to hide under my desk because there was nothing that was going to stop intercontinental ballistic missiles from reaching us.

Fast forward 55 years and I assume the US and Russia have developed anti-missile missiles to knock out at least some of the incoming nuclear-armed missiles during an all-out exchange.

How effective are US defenses against an all-out strike? How about NATO’s defenses or Russia’s defenses? I believe Russia developed a satellite that can shoot down missiles heading their way. Does the US have similar capabilities, or are we doomed?

Whatever happened to the Strategic Defense Initiative (SDI) or “Star Wars” from the Reagan era.

2

I’ll start with your last question–we are doomed in a large-scale nuclear exchange. Will it be a true apocalypse, or something less? That gets tough to speculate on, there’s been studies done, particularly during the Cold War about how many would be expected to die in the initial exchanges and it’s not a good number. The bright side is we have significantly reduced nuclear stockpiles since that time. We still have more than enough that every major city in both the United States and Russia would be quite likely to be struck.

I’ll then generalize a bit.

Neither the US/NATO or Russia have technology that is sufficiently reliable to trust against most nuclear delivery systems. Both countries have anti-ballistic missile technology. Some of it is even getting pretty decent, the most modern systems can hit a range of missiles with some degree of reliability.

I am not using the above words imprecisely–“pretty decent”, “can hit”, “some degree of reliability.” That all sounds okay if you’re talking about intercepting a conventional missile, where it sucks if some get through, but it’s good to take some out. With a nuclear armed missile even one failure is a catastrophe.

In a large-scale nuclear exchange, there will be more stuff coming in than we have deployed anti-ballistic technology to intercept even if it was all 100% reliable, and many of our deployments won’t be able to keep up with the number of incoming missiles.

Additionally mind that there are a number of different missiles that can carry nuclear warheads. In general, the faster a missile is traveling, the harder our present ABM technology has in intercepting it. Against short-range ballistic missiles that move fairly slowly, we have a number of weapon systems that are now quite reliable, but even they are not perfect.

For up to intermediate range missiles, we have THAAD and a few other systems that have some tested successes–reliability rates are lower with THAAD than with Patriot (a system for shorter range/slower missiles), because THAAD is attempting to shoot down faster missiles than a system like the most modern Patriots. The AEGIS system has somewhat similar operating parameters to THAAD–it has some tested successes against up to intermediate range missiles.

Now let’s get to the worst news–the worst odds we have of stopping a missile are from intercontinental ballistic missiles. The reason being, these missiles go quite high into the atmosphere and then come back down at a very rapid speed–they reach up to ~4 miles/s in speed in terminal phase. This is very fast.

[As an aside, this is faster than so-called “hypersonic” missiles, which may surprise people because some of the ICBMs that can reach these speeds are a good bit older design. This is because of different operating parameters and physics. An ICBM gets very, very fast because it goes way up in the sky (across the Karman line) and then down and reaches a high terminal velocity sometimes upward of 8x speed of sound. So-called “hypersonic” missiles generally refer to cruise missiles that are designed to get up to around 5x the speed of sound, which is a different scenario and has some potential tactical advantages when talking cruise missile technology.]

We have almost no tested history of successfully shooting down missiles moving at terminal speed of a typical ICBM–when I say almost, there have been I think one disclosed successful intercept of such a missile by an AEGIS system back in 2020. I am not sure any tests have succeeded or been attempted since then, and I think even that successful test was outside of the operating expectations of the system.

Russia has about 1400 of its warheads on ICBMs, that are at locations in Russia we cannot hit before they successfully launch. These warheads are on multiple-delivery missiles (so there are 1400 warheads, less than 1400 missiles), these missiles will launch and their boost phase will last 3 to 5 minutes. They will then begin their up to 25 minute midcourse phase during which they will enter sub-orbital spaceflight, reaching an altitude of up to 750 miles. Then they will begin their descent, reaching their terminal phase at 62 miles altitude, at which point they will be traveling many times faster than the speed of sound. Multiple projectiles, chaff, decoys and etc can be shot off.

Russia has a number of such missiles with operational ranges of 10,000-12,500 km.

They will have a number of different types of warheads ranging probably from 300 kilotons up to 800 kilotons, Russia still maintains some 1 megaton or greater yield warheads, but like the United States probably isn’t likely to keep them in a very ready state of operational use for various reasons (nuclear doctrine shifted towards more smaller warheads in the 80s and beyond.)

Using the well known tool at NUKEMAP by Alex Wellerstein (nuclearsecrecy.com) you can get an idea as to what a 500ish kiloton device can do. As a quick example I simulated one hitting Union Square, New York City. The fireball radius would be .73km, anyone in that is all but certainly killed. Up to about 8.9km radius the vast majority of people affected will die. Others outside of that radius will die from radiation and other effects, but with lower certainties and greater survival rates the further you get away. This doesn’t quite destroy New York City completely, but it comes fairly close. On Manhattan people north of Harlem have a chance. Far south Brooklyn, the eastern half of Queens, south of JFK etc would have highish survival rates. Most of State Island would survive as would much of the Bronx.

Another 1,000 of these dropping at every major and mid-size city around the country is not going to be a good time, and it is unlikely we will stop any meaningful percentage of them.

3

At the strategic level (ICBMs and the like), there isn’t any real anti-ballistic missile technology deployed in the US. The systems @Martin_Hyde mentioned are primarily intended to defend troops in the field or deployed garrison, or formations of warships.

The US was developing true antiballistic missile bases (as an outgrowth of anti-bomber surface-to-air missile systems) in the 60s and 70s, but abandoned it because of cost and limited effectiveness.

4

Sorry yeah–that is a good clarification, I wanted to talk about the capabilities of shooting the missiles down more so than anything else, but yeah in a large strategic exchange we don’t even really have any disclosed operational deployments of ABM systems that are even intended to do this. It is possible that you might have some localized AEGIS systems on ships make a half-hearted attempt, who knows–the vast, vast majority of the Russian missiles will be flying without any ABM challenge.

As a slight correction though, while AEGIS is primarily deployed for protection of Naval fleets, there is a strategic protection component to some AEGIS deployments that is in sort of an “in development” phase. THAAD is also more for strategic defense than point defense of military installations and fleets–the disclosed deployments of THAAD (domestically) are Guam, Wake Island and Hawaii, all there theoretically to try and stop an intermediate range North Korean missile if one was launched.

And of course, as I said, neither AEGIS nor THAAD’s operating parameters really suggest they can meaningfully succeed at shooting down long-range ICBMs in their terminal phase, discounting the one-off test of an AEGIS system doing that, these systems just aren’t expected to be able to successfully intercept missiles moving at that speed.

Additionally, AEGIS and THAAD are both significantly untested in real combat. The Patriot systems (which again, deal with relatively slow-moving missiles that are usually fired over shorter ranges), have a good service history now, but they have basically no bearing on the ICBM threat from Russia.

5

That isn’t really true; the somewhat awkwardly named Ground-Based Midcourse Defense (GMD) is an anti-ballistic missile system with 44 interceptors in silos baed in Ft. Greely (Alaska) and Vandenberg Space Force Base (California) and the Sea-Based X-Band Radar (SBX-1). The system is advertised to be intended against intercontinental-range threats from “rogue states” (read: North Korea) and would obviously be overwhelmed in a strategic exchange involving dozens or hundreds of ICBMs equipped with multiple independently-targeteted reentry vehicles (MIRV) not withstanding well-founded skepticism about the real-world reliability and capability of the system against an unannounced attack with weapons deploying countermeasures versus the orchestrated interceptor subsystem tests that are performed every few years as a ‘demonstration’ of operational capability.

There was discussion some years ago about basing a wing of GMD interceptors in Poland and (briefly) somewhere in New England as a counter to a limited strike from some unnamed European adversary (which would by default be Russia unless you think that France has secretly retained it’s land-based component of Force de dissuasion and has a long-standing unspoken grudge against the US, but as it stands the GMD system is not well-positioned to respond to missiles launched from Russian territory or SLBMs from the Barents Sea, so practically speaking it is true that there is no effective defense against an ICBM attack from Russia, and even the Safeguard System you cited was really only intended as a point defense system to protect Minuteman silos from a disarming first strike so as to ensure retaliatory capability.

Stranger

6

Thanks, everyone for the detailed responses to a complex question. The hope was that there was a secret program underway (Space Force?) to address this vulnerability, but it doesn’t sound like there is very much anyone can do. I suppose our only strategy is to launch a counterattack early enough in hopes of doing as much damage to the enemy as they do to us (Mutual Assured Destruction).

I assume that NATO countries are in the same position with regard to nuclear defense as the US, but what about Russia? Do they have any known capabilities to intercept our missiles, whether in space or elsewhere, or are they in the same boat as the West is in?

7

My apologies in advance for being pedantic, but (Mutually) Assured Destruction (AD; the first term was added by critics post hoc to make what I’m sure they thought was a clever acronym) is a strategic deterrence theory that is predicated on the notion that the guarantee that both sides will be obliterated would prevent either side from engaging in a unilateral disarming attack. If missiles are actually flying, the deterrence strategy of AD has failed by definition. Whether AD is a good or workable theory of deterrence is another question; as many critics have pointed out over the years it relies upon a number of assumptions (rational actors, accurate information about the opponent’s capabilities and intentions, reliable early warning detection and response capability) which may not hold in reality.

Russia has the A-135 ABM system which is a terminal interception point defense system more comparable to the US Safeguard system that @gnoitall referenced above than the US GMD system. It has been upgraded from the original A-35 system and since tested although how reliable it is and how the system would fare against multiple incoming threats is unknown. I would expect that against the many RVs that would be targeted at Moscow and surrounding areas in a strategic exchange it would be overwhelmed. The reality of ballistic missile defense is that any system can be defeated just by overtaxing the system with more incoming RVs than it can handle at once, and it is much easier to be the attacker than the defender, particularly with MIRV-capable systems.

Stranger

8

There’s been some talk of systems designed to take out ballistic missiles during the boost phase. The upside is that they’re easier to hit then, and they’re still over enemy (or at least not our) territory at the time. The downside is that your anti-missile systems have to be right next to enemy territory. I don’t think any of those proposed systems ever amounted to anything.

9

Or in orbit overhead.

That became one of the later architecture evolutions of Strategic Defense Initiative. Unlikely now with the whole international agreements about weaponizing space, and the difficulty of putting enough defense sats on station to make a difference without being easily overwhelmed.

10

The Kinetic Energy Interceptor started life as an ascent-phase interceptor, first as a mobile ground-based mode and then installed on sea-going vessels (which the Navy utterly disclaimed, wanting nothing to do with the program). Eventually it migrated away from ascent phase and into the post-boost “mid-course” phase (in between ascent and the ‘terminal’ reentry phase) because of the issue you describe of the interceptor having to be based somewhere relatively close downrange. The boost phase of an ICBM lasts around 150-180 seconds, so a defender has that much time to detect, discriminate, initiate launch, and intercept, so while the attacking weapon is going slower at this time than at any other time in flight, it is also isn’t going slow for very long. KEI was cancelled in 2009 prior to any test or even a fixed deployment scheme (at one point there was a proposal to gang launch them from repurposed ballistic missile submarines they way Tomahawk missiles are in SSGNs, which the US Navy was again reportedly not enthused about) and the institutional memory of the program has been almost eliminated to the point that it is difficult to find references online; aside from the GlobalSecurity.org page cited above and a Wikipedia article, almost everything else I found is archived or the same content. That was certainly a good use of several billion dollars of taxpayer funds.

I assume you are referring to Brilliant Pebbles and similar “Rods from God” concepts proposed during the Strategic Defense Initiative Organization (SDIO) days and even evaluated to proof-of-concept by the Ballistic Missile Defense Organization (BMDO), predecessor to the the current Missile Defense Agency (MDA) before being assessed as too costly and ineffective. Brilliant Pebbles wasn’t actually an interceptor program; the intent was to be able to strike at missile installations and mobile launchers on the ground, even those in hardened shelters and silos. It wasn’t then and isn’t today restricted by any agreements about weapons in space as it doesn’t have any kind of offense ordnance (nuclear or conventional) on the weapons, and doesn’t attack anything in orbit.

The actual weapons were quite cheap, essentially just being tungsten rods with a small guidance and propulsion system for targeting on descent prior to reentry. The overall cost of Brilliant Pebbles would have been extraordinary, however, given the launch capacity at the time; it basically would have required then-space launch vehicle contractors Martin Marietta and McDonnell Douglas (since absorbed by Lockheed Martin and The Boeing Company, respectively) to run production lines for Atlas II and Delta II rockets to be in constant, round-the-clock production (or multiple production lines established) to be able to deploy the system. At a cost around $US70M per launch circa 1995 that would have been at least $US140B in launch costs alone for a basic constellation capable of taking out ground-based assets in some reasonably narrow timeframe, notwithstanding any losses, replacements, counterforce attacks, et cetera. Of course, the system couldn’t take out submarine-launched missiles nor airborne bombers, and so was not really a complete solution anyway even if you had confidence in the ability of the system to materially disarm all land-based missiles.

Stranger

11

I see you mentioned airborne bombers. I remember learning as a kid that the US always had bombers in the air just in case they needed to be deployed over Russian territory. Is that still the case, and if so why do we need them if we have the missiles at the ready? Was this considered a first-strike capability since presumably they were close enough to get there faster than a missile could?

12

Nah, the Strategic Air Command (“Peace is our Profession”) deterrence patrols a.k.a. Operation Chrome Dome ended in 1968, ostensibly because the full deployment of the LGM-30F ‘Minuteman II’ (a substantial accuracy and functional improvement over the LGM-30A/B ‘Minuteman I’) meant that the US has substantial retaliatory and counterstrike capability absent of the strategic bomber fleet, but also because the B-52 was needed to participate Operation Rolling Thunder, the sustained bombing campaign in Viet Nam. At this point Soviet air defense systems were already proven enough that penetrating deep into Soviet territory with the B-52 was no longer realistic and what became the AGM-86 ALCM was still in early development (not deployed on the B-52 until 1980).

We still have B-52 and B-1 bombers technically on alert status (though not armed on the flightline) and the B-2 ‘Spirit’ stealth bomber ostensibly capable of deep penetration attack, although with the reduced fleet quantity and questions about how ‘stealthy’ it really is against modern low frequency radar it isn’t really a deterrent threat in and of itself. Nuclear bomber response has long been considered a second strike retaliatory capability after land- and sea-based ballistic missiles have been exhausted, or for use in ‘limited’ battlefield exchanges, although once you wipe out an opponent’s armored brigade with a single strike they are probably going to consider further conventional attacks pointless and start looking to their own nuclear arsenal in response.

Stranger

13

Nuclear bombers are part of the ‘nuclear triad’ which consists of bombers, land launched ICBMs and submarine-launched missiles.

The purpose of the triad was to make sure the enemy couldn’t decapitate the US nuclear forces in a first strike. Three independent systems, all commanded by different branches and in the case of subs potentially operating autonomously, was thought to inject enough uncertainty into any first-strike plan as to make it untenable.

Bombers also have an advantage in that they can be recalled if conditions change.

14

I know this is an old post that’s already been answered twice just above, but as to this last snippet …

Not even remotely. The perpetually airborne bombers of teh 1960s were in holding patterns a couple hour’s flying time from the Soviet border. And in most cases their targets were a couple hours flying time into the Soviet Union. So from the time the bombers would have gotten an attack order until bombs on target was 2-4 hours.

Conversely, the time of flight of an ICBM is and always has been on the order of 20 minutes from launch to impact. The bombers mostly predated the missiles, and were mostly withdrawn when the missiles became widely enough deployed.

15

I want to pile on and ask if these missile defense systems that we do have are implaced or utilized in a way that prioritizes what’s being defended (ie, the largest population centers, the seats of government, key military assets, etc)? I imagine so in some way (“we must save the President!”), but if so, how and what are the priorities?

16

This is what the US has, rather than what they might wish thyeycould develop or deploy at some future date:

Essentially it’s a glorified test system relabeled as real defense, and deployed where it has the best chance of atriting an attack by a handful at most of North Korean missiles. Those being the easiest sort to stop because they’re shortish range which correlates to low speed of descent relatively speaking.

So the deployment is not set up to defend the highest value US targets. It’s set up to defend against what we have some hope of actually slowing down or stopping, versus the stuff we have no capability to defend against at all. As well to defend against the one threat we felt was irrational enough as to be politically & militarily undeterrable.

Now that Putin has demonstrated that he too is that irrational, and Iran has demonstrated it intends to build missiles after the prior US administration unilaterally terminated their agreement not to, we can expect that whatever good Greeley might ever have done is an even smaller fraction of the threats we now face.

17

One slight nitpick: the Ground-Based Midcourse Defense (GMD) system is, as the name states, a mid-course interceptor that strikes the incoming weapon after the boost (ascent) but before the terminal (re-entry) phases of flight, essentially while it is coasting ballistically well above the atmosphere, hence why the actual interceptor vehicle is called the Exoatmospheric Kill Vehicle (EKV). The speed of the device isn’t as much of a challenge as discriminating it from decoys or natural heat heat sources (i.e. the Sun, because the ‘seeker head’ on the EKV has long had problems not getting blinded when in a Sun facing aspect) and the overall ability of the entire system to launch the interceptors in time to get into position for the EKV to make an intercept attempt,

In a real threat situation, multiple interceptors would be launched because while the Missile Defense Agency has never published specific Hit To Kill (HTK) probabilities, they are certainly not high enough to rely on a single interceptor, so you can easily see that the forty-odd GBIs deployed in silos would not be capable of defending against a similar number of individual threats. There are still open questions about the reliability of the end-to-end system including the Sea-Based X-Band Radar platform (SBX-1) which provides early discrimination and tracking but despite the fact that it is supposed to be based out of Adak Island in the Aleutians but has spent much of its time at Pearl undergoing maintenance and testing. Without SBX, the system has only very limited tracking abilities so getting interceptors close enough for a mid-course ‘kill’ is problematic.

The rest of your criticisms are en pointe; the system, as designed, would be overwhelmed by someone with even a small arsenal of not very accurate ICBMs; it has been ‘tested’ numerous times with only limited success in highly orchestrated tests geared toward ‘nominal’ operation instead of testing the boundaries of its capabilities; and whether it would work even against the ‘rogue state’ is in question but against a strategic nuclear strike from Russia or China it would provide effectively no defense.

Stranger

18

Thanks for the course correction and additional details.

The various other efforts for Aegis ABM & THAAD and all the rest are quite a cavalcade of defense contractors failing at great profit. This being FQ I must contain my cynical skepticism, but I have been reading of this effort weekly in AW&ST since I was a child 50+ years ago, with damn near fuck-all to show for it.

19

Aegis (Navy) and THAAD (Army) are theatre defense systems only really intended to protect against short range ballistic weapons. There were some efforts to try to extend both to more extensive capabilities (including a modified SM-3 in an anti-satellite intercept) but actually intercepting ICBMs is just beyond the physical limits of their boosters. The United States did once, briefly, have an operating terminal defense system (Safeguard) capable of intercepting incoming reentry vehicles (RVs) inn 1975; unfortunately, not only did it use nuclear-tipped interceptors (Spartan and Sprint) that would probably have done nearly as much surface damage as the weapons it would destroy, it was also only capable of point defense of a single missile wing (Wing VI out of Grand Forks AFB, ND), and at extraordinary cost that was deemed to be unnecessary and unsustainable.

Certainly, many contractors have made a meal out of missile defense even though we have little to show for it in terms of strategic deterrence or protection against anything other than a wanton attack by a rogue actor with a handful of weapons.

Stranger

20

Agreed. For the rest of the crowd just becoming acquainted with this topic …

See

and

These are the other extant US systems intended to do a certain amount of “sanding down” of any inbound missile flux. But more for a flux aimed at our allies than for one aimed at the homeland. GDI is the sole real (and pitiful) homeland defense initiative.

BMD is hard. Stupid hard. And stupid expensive. Like so much in modern warfare the only way to win is not to play.