Why do the nations in my world use tactical nuclear weapons but not strategic ones while still having both?

Question

Exactly what it says on the tin: why do the nuclear bomb-having nations in my world use tactical nuclear weapons but not strategic ones while still having both?

They're not launching ICBMs at one another, nor do submarines or bomber aircraft regularly play a part in nuclear warfare; the strategic nuclear capabilities of these countries, which are similar to real-life contemporary ones, are used as a deterrent, rather than as an active weapon on the battlefield.

However, quite a few more countries have tactical nuclear weapons than those possessing strategic ones, and nukes with yields of something between twenty tons of TNT and five kilotons of TNT are regularly thrown back and forth between battleships, tanks, infantry and artillery formations, and even aircraft.

Why do countries that have strategic nuclear weapons not use them while still regularly using tactical nuclear weapons in warfare?

Answer 1

"Limited nuclear war" doctrine is true

During Cold War, it was envisioned that the actual war can be played out in two scenarios - "limited nuclear war", fought over a relatively small territory with the help of tactical nukes, and "full scale war", in which every side would launch its entire arsenal of nuclear weapons. It was debated whether "limited nuclear war" was possible by itself, without necessary escalating into a full scale war. Fortunately, it was never tested in practice.

In your world, "limited nuclear war" was tested, and the test was successful - belligerents used tactical nukes against each other, but did not launch the bigger missiles. Since then it was considered acceptable to use tactical nuclear weapons without the risk of total mutual destruction.

Answer 2

Tactical nuclear weapons make economic sense for a country with limited military resources.

If you are a small resource-limited country country, does it make more sense to make a big nuke and threaten other big nuclear powers? Or a bunch of small nukes and use them against your peers in the sort of fights you routinely have? One big nuke means you probably never get to use it, so those resources just sit getting dusty in a silo somewhere. With a bunch of small nukes you use them all the time and they take the place of many conventional weapons, saving you money.

People with limited resources use their resources to make many small nukes because they are more routinely useful.

Answer 3

You can only have limited war when your war has clearly limited objectives. Somebody who is pushed to the wall will use everything.

Thus, you could see wars like Korea and Vietnam going nuclear without the big bombs being used, but something like WWII certainly would have used the big booms.

Answer 4

Strategic nuclear weapons have devastating environmental consequences.

Many people were afraid of what would happen when we first started using massive nuclear devices. Those fears mostly turned out to be wrong. We can use them with minimal consequences to the world at large.

In this world due to the atmosphere, soil, or something when you use strategic nuclear weapons it causes massive devastation, and a nuclear winter. It's devastating for everyone.

Using tactical warheads doesn't do this. Using nuclear weapons above a certain size is a diplomatic no no, and will make everyone unite against you for causing a nuclear winter.

Answer 5

There was no Hiroshima-Nagasaki equivalent in this world; consequently, nuclear weapons are not taboo, but they are still classified as weapons of mass destruction, if they are powerful enough. By generally accepted consensus, the limit is at 10 kTon, but nations pushing the limit are "frowned upon" in the international community, thus they usually stop at 5 kTon.

But the mutually assured destruction doctrine and the Samson option work as well as in our world - those countries just really hope they never have to deploy their multimegaton devices.

Answer 6

Nuclear Weapon Manufacturing Was Successfully Kept Secret:

When nuclear weapons were finally built, the physics of them was sufficiently hidden or obscure (possibly due to misunderstandings of physics) that only a couple of source nations really understand how they work. Other countries have tried and failed (spectacularly) to build nukes.

But in an effort to paradoxically keep a monopoly on strategic nuclear weapons, the originating countries conspired to maintain the secret by creating "black box" tactical nukes that self destruct if tampered with. They lied widely about how to build nuclear weapons, making it look like an even more dangerous process than it was, and based on subtly different physics.

Then they widely sold the "black box" nukes to other countries to reduce the need for these nations to build nukes themselves and discover the secret. Today, any nation on your world that wants a nuke can get one for the right price - far less than it would cost to build a nuclear weapons program themselves. Any country that builds a nuclear weapons program independently suffers a mysterious multi-megaton "disaster" at their facility.

Answer 7

It doesn't make sense

Making a critical mass of fissile material is expensive and the material is not scarce, but close to. Distilling Deuterium to add it to the bomb and turn it into a fusion bomb is expensive as well, but a little bit less. Tactical weapons may make sense in some cases, but always renouncing to the full destructive power at the same cost would be too expensive even for the richest armies.

Answer 8

International Treaties make the most sense as a the major limiting factor

Your question disallows any economic reasons not to use them, Therefore

The big reason you cant use technology to defend against nukes in our world

Assuming that both sides own or have access to the ICBMS capable of long range destructions. and access to large h-bombs. Whilst not yet suggested by anyone else here intercepting hydrogen bombs is impossible. Whilst long range bombers and ICBM's can be intercepted by rockets and missiles. Dropping a large bomb at the bottom of the north sea on a timer would create a tsunamis capable of drowning everyone in Vienna Austria. ICBMS were meant to quickly take out command infrastructure in the hope it would cripple more devastating responses. No missiles shield or submarine screen would prevent a Russian submarine for example from drowning the west coast of north-America by dropping a bomb past Hawaii The pacific is just too big for that. Therefore any technology solution to defend a nation from hydrogen bombs is very costly and unlikely. Unless said nation lives far away from any coast and I mean far far away like for example in the Ural mountains.

Treaties are therefore the only logical reason

For example a treaty could ban the use of any large bomb on a mostly civilian target. Even though in WW2 we bombed cities and factories regardless of status. nuclear bombs could be more severely regulated than other munitions. Maybe there is a committee of neutral nations that have to pre-approve the use of nuclear bombs' to make sure the wind doesn't blow radiation into other nations not related to the wars. Or there are designated warzones were certain types of bombs of limited strengths are allowed.

Another exception cloud be international waters away from coasts lines. This could mean that certain size war-heads could be pre-approved by treaty for use in international waters as long as its far away from a port city and does not create a tsunami too large.

There are myths out there that treaties like the Genève convention banned the use of triangular knife's/Bayonet's in warfare because it was harder to treat. Even though that fact isn't true its shows the perceptions that warfare can be limited and regulated affair.

Answer 9

Because attacking civilians is seen as abhorrent

The concept of Total War is much newer than most people think. The notion that the entire nation of your enemy is a legitimate target did not reach full acceptance until World War II.

So, in this world of yours, they simply have not thought of the concept of Total War yet. War is something that the militaries conduct between them, but civilians must(!) be left out, it is seen as a heinous war crime to attack civilians — in any way, shape or form — and that must be avoided.

Sure, the advent of strategic nuclear weapons has put the question on the table, because the obvious use of such weapons are to wipe out entire cities. However, it is also an absolutely abhorrent idea, and politicians and the militaries on both sides feel it would be the beginning of the apocalypse to remove the mindset, and instead make civilians a legitimate target.

As for why not use strategic weapons against large military targets, it follows that since there has been no real interrest in starting to chuck the long-reaching nukes, rocketry and missile technology has not developed like it did in real life, and the weapons are — therefore — simply not accurate enough.

Add to that local curiosities — like unpredictable weather systems and other phenomena that might throw weapons off course — and you have a genuine fear that the weapons might end up somewhere where you really do not want them, like on a city.

Answer 10

Transuranics

The bottom row of the periodic table looks like one of the most useless things in Creation. Nothing but unstable elements that can be made one atom at a time. But there's a reason for that -- no one has made the isotopes that have enough neutrons to be stable! Or at least ... no one is telling.

In your world, the cat is out of the bag. What we would call nuclear initiators - really, small nuclear bombs - using elements from californium on up are common. Such heavy atoms, with so many neutrons, might release five or six neutrons when they split instead of two or three - like switching from straight Covid to the Delta strain at the atomic level. A pinhead's worth of some of these isotopes can be a critical mass, and they contain much more energy per gram than uranium.

Under these circumstances, it has become tempting to use the mini nukes widely, and in the least expected places! But why not use the larger bombs? Well, because to have enough nuclear material to make a gigantic explosion ... you need to have quite a bit of nuclear material. Which produces neutrinos. And the enemy has very good neutrino detectors, so the moment you try to launch, they hit it with an interceptor missile loaded with a pinhead's worth of transuranic isotope, and that's the end of the large bomb. Neutrinos go right through the entire Earth, so there's no stealthing them. They can only be kept in bunkers as a deterrent for the case where there are so many bombs in the air no one can shoot them all down.