If it actually came down to it, would USA/Russian/China nuke major cities, or is that bluff?

[dead0man]

Russia is the only unknown here, and I doubt they would.  It's not 1963.

[dead0man]

I think all three would certainly try (why wouldn't they?), though there are definitely questions about things like Russia's ability to target locations very precisely. (Also, for all three countries, the decades-long pause in testing means we don't really know if any of them are actually nuclear powers -- it might be better to write something like 'presumed nuclear powers'. That said, the generally good performance of antiquated US tech in Ukraine is a strong sign that American military maintenance probably is up to par.)

I'm admittedly very biased, but I have full faith in the US's triad working good enough to get the job done.  (and that we wouldn't target population centers with no military value in such a situation, because why would we?)

[dead0man]

I question your premise.  When has any nuclear power demonstrated, even rhetorically, a willingness to use nukes against civilians?

Other than August 6 and 9th 1945?

they were both military targets.  Hiroshima was the military HQ for all of souther Japan.  Nagasaki was the most import port in the south and held a lot of military industry.  There was other things at play, sure, but there was military justification for the bombings.

<again, I'm admittedly biased>