There are three reasons why nuclear war might happen:
(1) “when you give up, you get it”—basic magical or Taoist principle familiar from everyday life, the moment you become exasperated and give up, I mean totally give up, looking for your keys then you find them.
In the same way, for about 40 years everyone waited for “it” to happen—the bomb to drop. Some people took this seriously, or pretended to—my mother, at least, said “we thought we wouldn’t be here in 10 years anyhow, so it didn’t matter”.
Not sure that was sincere, but there was a genuine expectation that it might happen—it was a real possibility.
Ergo, nuclear war would break out when everyone had totally relaxed, when it didn’t “seem real” anymore.
(2) “the 12,500 warheads”—nuclear stockpiles have declined from around 60,000 to about 12,500; contrary to expectations, in another paradoxical reversal (“if you want peace, prepare for war”), the decrease in stockpiles and readiness makes their use more likely.
This is because when there were “60,000 bombs” it really meant “the end” if a nuclear war broke out—prospective global annihilation. But with 12,500—yes, in theory it’s world-ending, but somehow we’re out of “total annihilation” territory into the bounds of “possible”, and possible without it being the end of the world.
(3) “nuclear doctrine”—countries like Russia, like America, have updated their nuclear doctrines to fight tactical nuclear wars (i.e. wars where you don’t obliterate the enemy, just take out “battlefield” targets and a few important cities).
So the actual policies in place account for a limited nuclear war—that wasn’t true in the past, it was more “MAD” (total destruction). So if people have planned for it then…
I would add as a fourth reason that people have used nuclear weapons in the past—now it’s just a fact that if people have done a thing once then they are likely to do it again.
In other words, sooner or later someone will use a nuclear weapon again—the odds are that it just has to happen. And it has been a long time since that happened now.
In a counterintuitive statement, America is more likely to use nuclear weapons than Russia.
That might sound crazy to you, because all the propaganda you hear is “insane genocidal Russians”, but think about two things:
(1) The only country ever to have used a nuclear weapon is America—they are the only country that “has form” with this weapon. If I showed you two men and I said, “This man has killed a man before, and this man hasn’t—but the latter talks about it all the time,” which one would you say was more likely to kill?
(2) Russia talks about nuclear weapons all the time, but talk is cheap—the more you talk, the weaker you are; and, further, the less likely you are to do something. America, on the other hand, never talks about using nuclear weapons (it’s the quiet ones who are dangerous).
How could that happen? Well, one possibility is a major Russian breakthrough, an unexpected breakthrough, against Ukraine that causes widespread confusion and, suddenly, the Americans drop the bomb because it is perceived that Poland is threatened, or the Baltic states, or by that stage Moldova is tangled up somehow due to Russian destabilisation efforts.
We already know there are British military personnel on the ground in the Ukraine (and so there are definitely many more Americans); so perhaps that would play in somehow.
How sure am I? I have a penknife I’ve had since I was 10 years old. It’s worth about £65, but it’s mainly sentimental value. I’d bet you that penknife that a nuclear weapon will be used, in a tactical context, in Europe in the next three years.