I think you're putting forward this fantasy of "a massive...

I think you're putting forward this fantasy of "a massive difference between tactical nukes and strategic ones" to get us used to the idea of a nuclear exchange. As soon as there is a nuclear exchange of any kind it will escalate to total nuclear war. That's because neither side can afford to take the chance that it will stop at one. Time is of the essence, if you delay it's your civilization that will be wiped out. This is not rocket science. Any school kid can immediately understand this but somehow you can't join the dots?