The West wouldn't be replying in kind with tactical nukes, because that leads to escalation as you said. It's about proportional cost imposition as a means of deterrence.[0]
It's also possible the opening salvo of such a response might see tactical nuclear deployments neutralized via conventional means.
Absolutely, I completely understand the idea and motivation, but I'm arguing that it's impossible, and so unlikely to be our plan. The entire reason tactical nukes are desirable is because they obliterate conventional forces, and Russia has thousands of them. And keep in mind "tactical" often kind of masks what these are - these are not glorified bunker busters.
The bombs that destroyed Hiroshima and Nagasaki, to several times larger, would generally be considered "tactical" in modern times. These are massive weapons. Then there's ADM/'nuclear landmines' [1], and more. In the absolute worst case scenario, there's even the possibility of transitioning to strategic weapons. Approaching this sort of battlefield with conventional forces is not a viable idea.
So I have no idea what the US will do if Russia resorts to nuclear usage in Ukraine, but I think this scenario can logically be discarded as one of the possible options. It plays well in the media, but it simply does not make any strategic nor logical sense.
>Approaching this sort of battlefield with conventional forces is not a viable idea.
It's almost certainly unstated US foreign policy on the matter, and not just a media bluff.
They might have thousands but they don't have thousands deployed. Moreover, use with any kind of frequency would just trigger a strategic US response, which would defeat the entire purpose—assuming there was purpose in the first place, which there isn't given conventional cost imposition.
Despite chill messaging, I suspect the US's strategic trigger finger is far itchier when things get real, and Russia knows this. Their triad has two arms which very possibly are entirely negated, and their C&C infra is garbage. There's a very real risk they'd just straight up die and accomplish nothing.
You're conflating the two types of nukes here. Tactical nukes tend to be just physically much smaller than strategic. They can be used in artillery, normal missile systems, mines, etc. For instance one defector even claimed that the USSR had developed suitcase nukes that they were stashing in various locations in the US, which would be easier than ever now a days. [1] There is no concept of deployment for these - it's simple and normal usage. When you speak of deploying, you're talking about strategic nukes. These are the absolutely massive weapons (both in terms of payload and also in terms of literal size) that are generally launching out on ICBMs. Russia has around 1700 strategic nukes deployed, and thousands of tactical nukes of all shapes and sizes.
All that said I do agree that this would result in mutual mass strikes with strategic weapons, and whatever tactical weapons may be appropriate for such a strike. This is why I think direct conflict with Russia, or Russia using nuclear weapons of any sort in Ukraine, is likely to escalate rapidly to what would be the defacto end of the world.
Read the above link. There are currently a minimum of 1,710 known deployed Russian strategic nukes. But speaking of a deployed tactical nuke is somewhat nonsensical. It's like talking about a deployed 155mm shell. Firing them requires nothing particularly unique and knowing the exact amount available is impossible, other than that it's certainly in the thousands. That's again the primary difference between strategic and tactical.
My previous reply was talking entirely about tactical nukes. They're not exempt from the concept of deployment. Even the Russians don't just let them float around willy-nilly. Most sit in storage.
>But speaking of a deployed tactical nuke is somewhat nonsensical.
The people whose job it is to track deployments of tactical nuclear weapons would probably disagree.
Well nobody is entirely sure how many tactical nuclear weapons Russia has. Nobody is really sure of much really. Do you remember that early propaganda wave about needing to only give Ukraine $xx billion more because Russian was imminently running out of missiles? It was Stoltenberg that called it the 'critical phase' of the war, then repeated by all the media, late 2022 if I recall correctly. Everything on these topics is at best kind-of-sort-of-not-really intelligent guesses. We can't even get the vaguely right ballpark figure for their conventional warheads, and there's minimal effort to keep that classified relative to nuclear.
But strategic nukes are a different beast those simply because of their size and requirement for specialized launchers, as well as their relative incongruence with conventional weapons delivery devices. You're not launching a strategic nuke out of a conventional rocket system (as could be the case for a tactical nuke) for sure! So this makes them, more or less, able to be reasonably estimated. It's still a pretty big guessing game, but it's generally going to be at least roughly in the right ballpark.
It's also possible the opening salvo of such a response might see tactical nuclear deployments neutralized via conventional means.
[0] https://www.csis.org/analysis/deterring-nuclear-weapons-use-...