If by “atom bomb” the OP means a fission device, then the reason hydrogen bombs were developed is rational, from a weapons standpoint.
Producing pure fissionable isotopes like U-235 or plutonium is the hardest and most expensive part of producing nuclear weapons. The hydrogen bomb (especially the fission-fusion-fission design using a U-238 casing) allows you to take the fissionable isotopes that would give you a 100 or 200 kiloton explosion at most, add on relatively cheap deuterium and lithium, and even cheaper leftover depleted uranium, and construct a 10-20 megaton bomb for much less than 100X the cost. “More bang for the buck” was the phrase in the '50s. This was not a negligable consideration when we had hundreds, not thousands, of nuclear devices and they were to be delivered by bombers that the opponent would do everything in his power to shoot down.
The example of WW2 scared the crap out of American war planners. They believed that the Soviet Union was a fanatically totalitarian country that could accept casualties and damage unthinkable to western societies if it would mean a victory for “world communism” (Think North Korea). Nothing less than guaranteed total annihilation seemed like an adequate deterrent.
What changed by the 1960s was design improvements that allowed you to use much, much less fissionable material per bomb than the 20 kilograms a Trinity-type device needed. Details are classified but evidently consist of better implosion geometry plus the use of D-T as a neutron source to boost the initial reaction. So the same stockpile of fissionable material can now be used for thousands of warheads. Since there are many more of them, plus they’re delivered by ICBM and need to lightweight anyway, plus they’re more accurate than older designs, the trend now is towards smaller devices. 100-300 kilotons is common. In fact, I don’t know if we still keep anything “on the shelf” much bigger than a megaton (1000 kilotons) anymore. Because of something called the square-cube law, all other things being equal lots of smaller explosions do more damage than fewer big explosions.
No such luck. The Deer People are vegetarians but they are fanatically devoted to their holy crusade to rid the universe of meat eaters. By their standards, we’re like the horrible brain sucking demons of so many movies and games. Their entire religion is based around the idea that God gave them sentience to rid the universe of the hell-spawned carnivores.
I don’t think this is true. A large bomb is always more destructive than a small bomb, the trick is just getting it in the right place. If your navigation isn’t very good, then yes, you need to carpet an area with bombs. And carpet-bombing an area with a few dozen 10MT H-Bombs tends not to be good for international relations.
According to an article I read last month , due to advances in navigation and delivery systems, the navy is now upgrading all its warheads from 100kt to 455kt for this exact reason. (“Superiority Complex”, July 2007, The Atlantic) Since they now have very accurate and survivable missiles, they’re putting more powerful warheads in them. This enables a fleet of nuclear subs to destroy most if not all Chinese nuclear weapons on the ground with a casualty rate in the 1,000-10,000 range. (Chinese missiles are liquid-fueled, which for various reasons have to be stored unfueled and require about an hour to fuel and launch).
Seen in this light, a defensive shield capable of mopping up just one or two incoming warheads would allow the US to mount a completely effective first strike against China with virtually no risk of large-scale civilian casualties on either side. There is essentially no nuclear threat from China anymore. Needless to say, this has China pissing in its pants, and this is exactly the reason they chose to demonstrate that they can pop GPS satellites if they so choose. If things went bad with the US, you could bet that an anti-GPS strike would be their first move. And to answer the OP, this might be one reason a country would want a larger weapon… if there is a chance that only one warhead from your first strike might survive, you want to make it pretty damned horrific.
[QUOTE=Lumpy]
Producing pure fissionable isotopes like U-235 or plutonium is the hardest and most expensive part of producing nuclear weapons. The hydrogen bomb (especially the fission-fusion-fission design using a U-238 casing) allows you to take the fissionable isotopes that would give you a 100 or 200 kiloton explosion at most, add on relatively cheap deuterium and lithium, and even cheaper leftover depleted uranium, and construct a 10-20 megaton bomb for much less than 100X the cost…What changed by the 1960s was design improvements that allowed you to use much, much less fissionable material per bomb than the 20 kilograms a Trinity-type device needed. Details are classified but evidently consist of better implosion geometry plus the use of D-T as a neutron source to boost the initial reaction. So the same stockpile of fissionable material can now be used for thousands of warheads. Since there are many more of them, plus they’re delivered by ICBM and need to lightweight anyway, plus they’re more accurate than older designs, the trend now is towards smaller devices. 100-300 kilotons is common. In fact, I don’t know if we still keep anything “on the shelf” much bigger than a megaton (1000 kilotons) anymore./QUOTE]This is all more or less correct. You literally can’t scale a pure-fission weapon, or even a boosted-fission device (the type Lumpy describes as using a D-T fusion source to boost neutron output and total yield) on megaton scales, because the weapon will blow itself apart before it can get anywhere near comlete fission. A multistage fusion device, however, is at least in theory unlimited to how large you can make it, though there are practical considerations that probably place some as-yet unexplored upper bound on yield. (The largest ever designed was the Soviet “Tsar Bomba” with a theoretical yield of 100MT, though it was intentionally downgraded to ~50MT for testing.)
The largest devices ever fielded by the United States was the B53 gravity bomb and the W53 warhead deployed on the Titan II ICBM, with a nominal yield of ~9MT. These were intended to be used as “bunker buster” bombs against hardened targets with very low altitude bursts. The W53 was retired and disassesmbled for recycling and A&S in 1987 when the Titan II fleet was deactivated. The B53 is currently not in the operational stockpile but many are still held in the Hedge portion of the Enduring Stockpile in case of need. Other strategic scale devices in current operation include the B83 (~1.2MT, gravity bomb), the W87 (300-475kT, MMIII and the now retired PK), W88 (~475kT Trident II D-5), and the various members of the B61 familiy (varity of load options including tactical variable “Dial-A-Yield” output from 0.3-170kT to ~300kT).
The original need for large multi-megaton yield thermonuclear (fusion) devices stemmed from two issues: the lack of accuracy and uncertainty of delivery methods (of several targeted weapons, only one might actually survive delivery and hit within its lethal radius); and the fear–which turned out to be legitimate–that the Soviets were working along similar lines. With the advent of highly accurate MIRV ICBM/SLBM delivery systems in the 'Seventies, plus computer simulation and a compilation of emprical test data that allowed the use of significantly less material in the Primary to achieve the same yield, the perceived need for massive megaton warheads became much less and designs turned more to compact, lightweight concepts that would be delivered in salvos. As Lumpy suggests, high yield devices are inefficient in terms of practical destructive results compared to a distribution of lower yield devices, and the CEP of late model Minuteman III and Peacekeepers was such that one could place reentry vehicles (RVs) right in the middle of a missile complex, industrial center, or region of a city.
In any practical sense, nuclear weapons are useless in combat. Any use of nuclear weapons–the ultimate in “total war”–even in a supposedly tactical context will almost inevitably lead to retaliation in kind and on a larger scale, resulting in a destructive exchange in which the “winner” is the one who manages to maintain some kind of post-exchange civilization. Nuclear weapons are really a diplomatic tool, as stupid as that sounds, and the danger is that someone along the line doesn’t realize that there’s no advantage to actually using them. This makes it very dangerous to puncture the myth that some kind of misparity or superior strategy will give a real advantage. Dead is dead.
This is all more or less correct. You literally can’t scale a pure-fission weapon, or even a boosted-fission device (the type Lumpy describes as using a D-T fusion source to boost neutron output and total yield) on megaton scales, because the weapon will blow itself apart before it can get anywhere near comlete fission. A multistage fusion device, however, is at least in theory unlimited to how large you can make it, though there are practical considerations that probably place some as-yet unexplored upper bound on yield. (The largest ever designed was the Soviet “Tsar Bomba” with a theoretical yield of 100MT, though it was intentionally downgraded to ~50MT for testing.)
The largest devices ever fielded by the United States was the B53 gravity bomb and the W53 warhead deployed on the Titan II ICBM, with a nominal yield of ~9MT. These were intended to be used as “bunker buster” bombs against hardened targets with very low altitude bursts. The W53 was retired and disassesmbled for recycling and A&S in 1987 when the Titan II fleet was deactivated. The B53 is currently not in the operational stockpile but many are still held in the Hedge portion of the Enduring Stockpile in case of need. Other strategic scale devices in current operation include the B83 (~1.2MT, gravity bomb), the W87 (300-475kT, MMIII and the now retired PK), W88 (~475kT Trident II D-5), and the various members of the B61 familiy (varity of load options including tactical variable “Dial-A-Yield” output from 0.3-170kT to ~300kT).
The original need for large multi-megaton yield thermonuclear (fusion) devices stemmed from two issues: the lack of accuracy and uncertainty of delivery methods (of several targeted weapons, only one might actually survive delivery and hit within its lethal radius); and the fear–which turned out to be legitimate–that the Soviets were working along similar lines. With the advent of highly accurate MIRV ICBM/SLBM delivery systems in the 'Seventies, plus computer simulation and a compilation of emprical test data that allowed the use of significantly less material in the Primary to achieve the same yield, the perceived need for massive megaton warheads became much less and designs turned more to compact, lightweight concepts that would be delivered in salvos. As Lumpy suggests, high yield devices are inefficient in terms of practical destructive results compared to a distribution of lower yield devices, and the CEP of late model Minuteman III and Peacekeepers was such that one could place reentry vehicles (RVs) right in the middle of a missile complex, industrial center, or region of a city.
In any practical sense, nuclear weapons are useless in combat. Any use of nuclear weapons–the ultimate in “total war”–even in a supposedly tactical context will almost inevitably lead to retaliation in kind and on a larger scale, resulting in a destructive exchange in which the “winner” is the one who manages to maintain some kind of post-exchange civilization. Nuclear weapons are really a diplomatic tool, as stupid as that sounds, and the danger is that someone along the line doesn’t realize that there’s no advantage to actually using them. This makes it very dangerous to puncture the myth that some kind of misparity or superior strategy will give a real advantage. Dead is dead.
On a serious note, atomic weapons are destructive but they’re hardly the endpoint in destruction - Japan was attacked with atomic weapons and it’s still there. Even the most powerful atomic weapons we have will basically destroy a city and most countries have lots of cities. So asking why we need a weapon more destructive than the atomic bomb is like asking why we need a weapon more powerful than the airplane or the machine gun or the crossbow or the chariot (all weapons which at one point were considered the “final” weapon).
FWIW, Ralph Peters thought of a weapon much deadlier than a nuclear bomb. It was a neural scrambling device that disrupted soldier’s voluntary nervous systems. So after it went off, you would have everyone in the area of effect still alive, fully conscious and fully unable to do anything. If a million soldiers were hit by it, you had a million invalids to look after, putting a huge backwards drain on resources. Mercy killings would be out of the question. So that would be much more destructive in that it would reduce your million man army to a million invalids requiring constant care, who most likely need several million people to look after them. And it would leave infrastructure untouched. (This was a plot in his War in 2020 novel.)
On the other hand, if you merely wanted to really wreck shit, you could use my very own gravity bomb idea. Imagine if you had a device that turned your local gravity from 1g pulling down to about 2 or 3g’s pulling straight up. So when it goes off, you and everything around you falls straight up for a few seconds and then back down. Unless everything you own is anchored to the floor, it would make one hell of a mess and would require one hell of a cleanup. It would be made all the more difficult by the fact that everything would still be roughly where it used to be, just smashed to bits. See New Orleans post-Katrina for example. Destruction? Atomic bombs are so 1945.
Except that the Chinese have nuclear submarines and MIRVs. Which means that they’ll be able to kill quite a few cities even if we destroy every land based missle site.
Well, I’ve been reading for years that the trend is toward smaller, more accurate warheads, and the stated composition of our stockpile appears to confirm such a trend. If that article is accurate it represents shiny new theory and not current practice, I’m guessing.
But regarding your first paragraph – with any explosive, the damage is worst at “ground zero” and falls off rapidly over distance (the square-cube thing). It is simple physics that, in hitting any distributed target (such as housing or hardened nuclear silos or aircraft revetments – and you can bet it’s an absolute article of faith to disperse military targets that might get nuked), multiple warheads, even if smaller, beat one big one. Five 200 kt jobbers will do a lot more than one 1 megaton, if spread the right way. Modern increased accuracy allows us to spread them accordingly, and MIRV technology means five are exactly as likely as one to survive and be nasty, since they’re all in the same missile.
Also, I’m completely taken aback by your assertion that a large nuke will be more diplomatically acceptable for good relations than several small nukes. That sounds like something General Buck Turgidson would say. “International relations” are effectively over once you’ve dropped a multi-megaton city-smasher on someone.
What it ultimately comes down to is the distribution of the targets and your faith in accuracy. Given a certain small-area target, if you’re sure you can hit it accurately with one vehicle, then it’s better to hit it with a stronger warhead than a weaker one. It saves missiles and it saves unnecessary collateral damage. If you have low-accuracy targeting, or the target is broadly distributed, then of course attacking a large area is better. If you’re sure of meeting your military objective, isn’t it better to avoid civilian casualties?
Again, it all comes down to target distribution, and I guess if the Navy is upgrading their weapons yields, then for some reason they must think their targets are less distributed than the rolling missile fields of North Dakota. It’s not something I just made it up, *The Atlantic *is a pretty reputable and respected publication.
If a near-Earth object, comet, meteor or other bit of cosmic debris were coming right at us, we might need something with a lot more bang to either divert or vaporize it.
Whether wilfully or in ignorance, you are misrepresenting the situation here. First of all, there were never any plans to “[carpet bomb] an area with a few dozen 10MT H-Bombs”; the largest warheads in the United States nuclear arsenal from the mid-Sixties onward were the aforementioned W-53 devices with a 9MT yield, and these were delivered either via the B-52 bomber or the Titan II ICBM singly to hardened targets.
Second, the “accurate and survivable missiles” you cite (the Trident II D5) were deployed operationally starting in 1990, so these are nothing new. They are more capable (range, throw weight, accuracy) than the Trident I C4, but they were all initially intended to carry the W-88 warhead in the Mark 5 RV, and more of them, with a design capacity for (12) RVs as opposed to (8) W-76/Mark 4 RVs on the C4, although budget limits and treaty restrictions scaled it back to the same loadout as the C4, and later down to the current (5). The deployment of W-88s was halted by the shutdown of Rocky Flats in 1989 due to safety and environmental concerns, and it was then estimated that there were enough warheads to fully outfit only 3-4 Trident submarines (500-800 warheads, depending on loadout).
The replacement of W-76 warheads with W-88 devices on the Trident II D5 SLBM is a result of a number of factors. Primary in these factors are restrictions on MIRV loadout of SLBMs and total active stockpile size imposed by the START and SORT treaties. Because the current loadout has been reduced to 1/2-1/3 of what the Trident II can carry, it makes more sense to install modern, high yield devices, and spread them out over more boats. In addition, the W-76 (~100kT) is an older design that is widely regarded as being a flawed and potentially unreliable. The W-88 warhead (~450kT) is a much newer, more compact, and better tested design that is considered signficantly more reliable; in fact, along with the W-87, it is the most modern weapon in the active stockpile (though curiously it lacks some of the safety features in the W-87 and has a “C” safety rating). The W-76 is no longer in manufacture, though there is a reliability and refurbishment program, while there is the intent to maintain manufacturing capability for the W-88 pits (although the lack of plutonium generation capability means we currently can’t produce raw material). Both will eventually be replaced, at least in theory, by the Reliable Replacement Warhead of intermediate or variable yield.
Chinese ICBMs are based in hardened silos located in mountainous regions. Striking at them while in-silo is likely to be very difficult. The older Dongfeng 4 & 5 ICBMs are liquid fueled, and those stored in mountain bunkers have to be fueled and elevated for launch, a process that requires more than an hour. However, striking at these with a ballistic RV while in the housed state is probably very difficult. There are also hardened silo-based DF-5As that are reportedly kept in a ready-to-fire state, and are surrounded by a large number of decoy silos, making an effective pre-emptive strike difficult. The more DF-31 and its naval complement the JL-2 are solid motor three stage missiles of unknown range which can presumably be launched within spare minutes if not seconds of the launch order, similar to Minuteman or Trident.
I don’t know where you get your casulty rate of 1,000 to 10,000, but it’s unmitigated horse manure. You’ll kill that many in military personel alone, and even if the missiles are located in remote regions the large fallout clouds that would result from a low altitude or ground penetrating burst required for destorying missile complexes would effect hundreds of thousands if not millions. The notion of a surgical nuclear strike is a patent absurdity.
Without getting into a debate about the merits and motiovations for the so-called “missile shield” provided by the Ground Based Midcourse Defense system, I’ll note that despite being declared operational the better part of two years ago the system has never seen a realistic full-up test. It is presumptious, at best, to claim that it would “allow the US to mount a completely effectives first strike against China with virtually no risk of large-scale civilian casulties on either side.” If there is anything that will prevent American casualties its the likelyhood that the relatively primitive Chinese ICBMs are not reliable enough to accurately hit US metropolitan centers at the bleeding edge of their range. An exchange would leave China with tens of thousands dead at a bare minimum, and likely millions dealing with persistant radioactive contamination.
US intercontinental ballistic missiles are in no way dependant upon the GPS system navigation; they use internal guidance with stellar navigation backup. Cruise missiles like the Tomahawk do utilize GPS but not exclusively, and can fully achieve target goals even if GPS capability is lost, albeit possibly with a modest decrease in precision. Knocking out GPS satellites would complicate naval maneuvers, but would have scarce impact upon ICBM/SLBM capabilities.
Than nukes? Suppose you had bio-engineered a new strain of anthrax-no antibiotic is effective against this. You manage to disperse this stuff in a fog, over NYC, washington DC, and Los Angeles. Within 24 hours, people start getting sick-local hospitals are overwhelmed in days… Now, you have police and the military getting sick as well-so the local government breaks down. all without destroying a single building!
Not likely. Even the most virulent weaponized bioengineered bacterial micro-organisms don’t survive very well in open, unprotected environments, and viruses are destroyed rapidly by even modest exposure to UV light, making wide aerosol dispersal almost useless. Contaminating municipal water supplies isn’t terribly effective, either; modern water treatment systems (where used), while not specifically designed to prevent biowarfare contamination, will pretty much eradicate the built of contaminating microorganisms via a combination of UV and MIOX-type ion purification. Bioweapons are mostly useful as a public terror tool rather than a practical weapon. Chemical neurotoxins are somewhat more effective and can even persist for weeks in arid environments, but will break down pretty quickly if there is environmental water, making them a poor choice in most areas of the United States.
Strategic-class nuclear weapons are clearly capable of more wholesale destruction and death than other forms of mass destruction.
This is apples and oranges; no nuclear weapon of any reasonable size will “vaporize” a meteor large enough to do serious impact damage. You’d want to design a nuclear device to divert an oncoming meteor, and the output would depend on a number of factors, including distance, speed, and so forth. The primary thing, however, would be directing the output such that it doesn’t just fragment the meteor and make a bunch of small, equally dangerous chunks, if possible. To that end, you’d want to design a purpose-build device that would convert the energy of the physics package into a relatively modest kinetic energy impulse. To this end, you’d probably incorporate some kind of polymer “shield” that would absorb the x-rays and vaporize into a low mass, high momentum cloud that would gently push the body to the side. It would likely be more effective and redundant to use multiple devices than a single, uberpowerful device. But this is all speaking through hats; we have neither a nuclear design for doing this nor a delivery system to get it there, so worried are we about terrestrial threats of ephemeral nature.
