An excellent discussion
On balance, I do not believe the USA would readily engage in a direct nuclear exchange with Russia. I believe it would want to limit the battlefield to Europe.
The USA has the advantage of being far away enough to insulate its population from the major horrors of war. Moreover, the Americans understand the devastation consequential to such a war. There would be no good options or outcomes for either Russia or the USA. President Reagan was well aware of the huge price the Americans would themselves pay, whatever cost was inflicted on Russia and its people.
But the Americans would survive virtually intact in any exchange solely between Europe and Russia, on European soil.
At present, it is not so much a question for Russia whether to use nuclear weapons or not as it has very powerful conventional weapons that can do enough damage to change the political and military dynamics. The puzzle, to me at least, is why they have not done so already.
President Putin is not the evil madman he is painted as by the propaganda of western media. It seems to me he is looking ahead to a post-conflict relationship with Europe (and America) which he does not want to prejudice by annihilating his main neighbours and alienating their people.
We forget that, when he came to power, President Putin was very westward looking and even wanted Russia to join NATO, as did his predecessor (who was misled by President Clinton). But he is no sop; no pushover who would stand by and silently allow the continued humiliation of his country by the USA since the collapse of the Soviet Union.
The west's insistence on a path of humiliation and resistance to the resurgence of the Russian state, through its support of proxy strategies, has in fact been highly destabilising. But all of this is not without limit. And, it seems to me, that limit would be anything that brings the war home to American soil.
President Putin did not react to the US sponsored invasion of Russian soil, when Ukraine (and some other nameless nations) crossed into Kursk. But, although he is a patient man, he must surely have a limit to what he will tolerate. I think domestic pressures may well soon force his hand.
If we had leadership in Europe and NATO that actually understood geopolitics it would probably stop pushing escalation. Unfortunately, it is weak, inexperienced and thinks it can project strength by using aggressive war rhetoric, without understanding the ramifications.
This why I am worried that we are being led along a path that takes us over the edge, by leaders without any ability to read a map.