Then came the horror of it all and Europe's upper classes had their youngest and brightest massacred and values changed. Warriors were now ordinary suckers and the elites kept themselves above the churn. War became a business of calculated leverage. It on that massive change in context that we changed together to deciding that war is not always such a good idea.
Then on top of that conflicts like those Vietnam and Afghanistan merely emphasize the baseness and poor value return of armed conflict. What was a sure thing before WWI was a daring bet in the nuclear age an nukes were only one factor involved in that calculation.
No we don’t. The biggest ever was Tsar Bomba, which was 50 Megatons with the option to make it 100. The aircraft that dropped it barely got out of the way in time, and it was only on a plane at all because it was too big and heavy for a missile.
Do you think they stopped because dropping the Tsar Bomba at full yield was a suicide mission? Yes, yes it is possible that it would have been. That would not have stopped development. Suicide missions happen. We have autonomous planes now.
There's only mild speculation in the >100MT number. They almost certainly exist, and your counterexample is right on the line.
Exactly what one-offs the russians once made, I don't know how well this is known. But we have a pretty accurate picture of the stockpile of bombs existing now. And the the age of maximally-huge bombs was a long time ago, to compensate for terrible missile accuracy.
On top of this there is undoubtedly genuinely secretive developments. I think it's improbable that all nations who signed the nonproliferation treaty have not chosen to develop nukes. This comes in two forms. The first is larger nuclear powers such as USA/Russia/China not expanding or modernizing their arsenals. The second comes in smaller nations not creating their own. For instance South Africa, during its apartheid years, managed to secretly develop nuclear weapons which it subsequently dismantled before handing power over to the new non-apartheid government. Another possible, if not likely scenario, is entrenched nuclear powers aiding in the development of nuclear capability of smaller allied nations as a means of ensuring those nations sovereignty and as a solidification of their relationships. As an example of this, the US has for decades been alleging that China has been helping to enhance and expand Pakistan's nuclear program. In times past it was alleged that Israel had played a role in the development of South Africa's nuclear program.
Tsunami weapons are also a game changer. They don't suffer from the same issues of delivery that land/air based weapons do and may be more able to effectively sidestep missile defense systems, and of course also dependent on absolutely enormous payloads.
While I'm very doubtful that the US or Russian stockpile contains a > 100MT warhead, I agree that if there was any serious reason to produce one, this need not take very long, nor attract much attention.
Large bombs are in the ballpark of earthquakes, for energy released. But how much of this would be contained in the water, not just blown into space, or something? Presumably someone has done the calculations...
As I understand, “develop” is a bit generous; it was largely direct transfer from Israel.
> Another possible, if not likely scenario, is entrenched nuclear powers aiding in the development of nuclear capability of smaller allied nations
How is that not likely? Most current (and the few past) nuclear powers that aren't the US, Russia, or perhaps Israel benefited from this at some point in their programs, covertly or overtly.
The thing that's stopped countries from war has not been trade, amicability, social evolution or anything besides nukes. The reason no developed nations ever go to war is because there is no win condition. If one side or the other is facing significant losses, they will retaliate with nuclear weapons. If that doesn't end the war immediately - it'll shortly result in a flurry with both countries effectively ending each other instead. Mutually assured destruction, as a term, always felt like it somehow missed some of this nuance!
The thing that ought actually concern people is the development of anti-missile technology which is rapidly advancing. Highly effective anti-missile technology would signal the return to war. This is why countries such as Russia have been developing things like 'Tsunami Weapons' [1] - a nuclear weapon designed to be detonated under the ocean that could generate radioactive tsunamis thousands of feet high. If that sounds difficult to believe consider that we have nukes in excess of 100 megatons now a days. Hiroshima was 16 kilotons - in other words about 6,250 times more powerful.
The point of this being is that I think this will help create a multipolar world and industry - imagine e.g. a new Chinese OS competing against Android/Apple. But I do not think that the current status quo of the world has been playing a meaningful role in deterring war anymore so than a change to a more multipolar world will advance it. I think it's simple. When we can't overcome nukes, we won't have "outright" war - creating an allowance for proxy wars like Vietnam where no nuclear participant's sovereignty is at stake. When we manage to overcome nukes, we will have outright war.
[1] - https://www.rferl.org/a/russia-launches-new-submarine-believ...