@MihndarWe are set 20 whole years after WW3. The war
ended in 2030.Our current date is
2050.
Just like the example with the recent war declaration on the Caliphate I see that people have problems gasping the distance of time.
I repeat it has been 20 whole years since WW3 ended. That's relatively a ton of time.
For example I used this to form a large kingdom with the development level comparable to the leading nations in the setting.
The Soviet Union developed their own nuclear weapons under 3 years, even if we include the start of their nuclear researches till the first test (1942-1949) it'd only count for 7 years.
And that was a whole century ago.
By our age nuclear physics are pretty much part of our everyday technology and then imagine 2050.
Yup, it wouldn't be surprising even if a nation just pops up with nuclear weapons under a year or two.
Nuclear prohibition would be nearly useless because of the pure fusion alternatives.
Anyways, the only current missile which is in the excess of the 30Mt combined yield is the R-36 which is steadily decommissioned and limited in overall count to less than a hundred such missiles. Yes, 10 bombs with combined 30+ Mt yield can level most metropolises in the world but such event was already discussed before.
You can call such all out nuclear bombing the apocalypse but the fact is a major part of humanity and our civilization will survive. At worst the radiation will cause some deaths even centuries after the war and it'll remind us of such terrible and ancient folly.
But destroying ourselves? Hah, even if you split the current nuclear firepower into hundred times more warheads as MIRVs (which is impossible for technical reasons) I doubt it would be anywhere enough to destroy life on our planet.
It'd do about 10 times more damage, though. Both direct and indirect.
It's the same with the cold war era arsenal.
the idea of 1 bomb per city works only on paper. Sure, a multi-megaton nuke exploding over a city would destroy quite a large portion but not all. Indirect effects are the same.
Some theorize the so-called "nuclear winter" but the biggest problem with that nuclear explosions are pure energy compared to volcanos or meteor impacts. Meaning it can't move so much dust as these and then you have to consider that airburst detonations only raise fraction as much dust as ground contact detonations.
So yeah, chances are high it won't change our weather the slightest bit.
Long story short there are swarms of natural disasters that could destroy humanity far worse than an all out nuclear war does.
Again, nuclear wars are terrible. But don't be so drunk on our powers.
We would currently struggle to deal with any incoming asteroid, for example.
We may find solutions in the future but even if our ICBMs could be easily used to target asteroids our oh-so-terrible nuclear arsenal would at best only help us to redirect the asteroid a bit so it would miss us.
Also back on acquiring nukes. We are in 2050 and use orders of magnitudes more energy than we do right now. To put in perspective, we have kW range consumers and with railguns and alike we would need to switch to the MW range. You can bet that nuclear power would be far more widespread, preferably with large plants gradually replaced with the new and clean fusion reactors. Containing the heat is somewhat plausible albeit we would need high temperature superconductors and of course something to "catalyze" the reaction (like antimatter) to make it worth the effort to begin with. Still, by 2030-2050 it should be plasuble by any but the most pessimistic estimate.
And with widespread nuclear power comes the even more through application of it in the military.
I already told you how "easy" (relatively speaking) for a country to become a nuclear power in this setting. Nukes would be be a in use by any developed nation, to say at least.
While I'm not sure on strategic warheads but many countries should pile up massive amount of tactical warheads which pales the Cold War in comparison.
In such a world a flexible nuclear warfare policy is a must.
Like I said there's a huge difference between using sub-kiloton tactical warheads, kiloton-yield cruise missiles or SRBMs, and large strategic ICBMs (MIRVS or otherwise).
And these are just their measure of power. We also have the method of application. Using nukes to knock off satellites in space, using nukes to destroy armies or large military, using high altitude nukes to knock off civilian electronics, and outright dropping nukes on cities. The difference between them are huge.
All of these have different levels of severity, and just like how Kennedy realized this you should be aware that a policy which doesn't allow for different measures for different situations is no deterrent. It's actually an alibi for a terrible all out nuclear war.
So if you don't wish to have actual nuke-spammy wars, I suggest adopting a flexible doctrine with them.
For example with clean and sub-kiloton yield nukes I can easily see them being occasionally used for mining and excavation purposes. Teller at the time was a bit crazy to suggest this but without any fissible material and the explosion being sufficiently low yield that it won't spew too much dust into the atmosphere, it's doable. (Teller's original idea involved dozens of buried multi-megaton nukes, so go figure)
You have to realize that nukes are basically nothing but very weight-efficient explosives.
EDIT: Regarding antimatter.
Well, there are multiple proposed ideas to its generation but without space development I say the most plausible is to use various colliders.
Technically the conversion achieved nowadays is ridiculously inefficient but if made by engineers it was suggested to go up to 0.01%. I think by understanding the mechanism better which is inevitable this can be raised to at least 1%. Laser induced mechanisms are another way.
As for storage, currently the antimatter trap is roughly this size:
Some obvious issues aside you can actually carry this around. Artistic presentation of what would be a soon to be portable antimatter storage unit:
Also I suppose when storage time doesn't need to last for months and hold back miligrams of particles then perhaps more compact measures are possible. Although it's of course just extrapolation on my part.
BTW, another possibility for holding antimatter? Yup, carbon-nanotubes. If done right you can actually squish quite an amount of antimatter into these.
I guess, as always, CNT is the answer to such issues. Nanotechnology rules!