in hindsight the issue was that the kinetic possibilities (hey here are all these tanks on the Russian side of the border) were not given as much weight as the speech (just some war exercises). in hindsight a variety of approaches could have been done, for example if NATO sent a "just an exercise bro" series of tanks to Ukrainian side of the border, exactly matching the number of Russian tanks, not exceeding them, then, obviously, the kinetics of the Russian invasion would have been different (impossible).

That's the game theory anyway, I thought that it's better just to go for peace.

So with this hindsight knowledge (tanks = invasion) isn't the real question now, where are the tactical nukes? Should they be matched (insanity for insanity)?

If before 24th of February NATO tanks had matched Russian tanks, under the guise of a war exercise, Russia wouldn't have crossed the border with tanks: they couldn't have - there would have been tanks across the border.

What is the tactical nuclear missile equivalent? What physically mirrors or counters or makes it impossible?

I guess there need to be tactical nukes aimed at all of the command centers that could order a tactical nuke, and then this needs to be publicized.

It would surprise nobody to learn "Hey Russia just nuked Ukraine". Not a surprise to anyone, because it metaphorically just happened days ago. We need to learn from what happened days ago. Time to dust off the old nuclear playbooks.

Its naive to think US didnt fully expect the war. They were the first ones to move diplomatic staff and special assets. If anything sudden withdrawal might of secured a comfortable crisis just in time for 2024 elections.