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

[Beet]

This is one of those things where the less people think it could happen, the more likely it is to happen. By the way, I still remember a coworker of mine suggested nuking Mecca back in around 2011. I don't remember what the context of it was, but there was nothing going on in the international stage that would have caused it. IMO whether by terorism or war, its only a matter of time before a major city is nuked.

[Beet]

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>

These types believe that if there are civilians present then it immediately ceases to be a military target. That's why it's so impossible to discuss anything with these people. I wouldn't even be surprised if they'd say Hitler's bunker wasn't a military target because his secretaries were there.

When you kill 80,000 people with a nuke, it's a civilian target. Ironically the Hiroshima nuke killed more US citizens than any other bomb in history.

Ultimately, if there's one civilian there, some people will say it's a civilian target. Otoh, if there's one soldier there, someone will say it's a military target. Thus, the whole military/civilian targets distinction is worthless. Everyone will have a different opinion. But we are the only ones who have used nukes in war, indisputably.