I don't want to sound like a sociopath. Russia was the only real threat to global security after the fall of the Nazis. Stalin wasn't exactly best friends with the West. It seems a lot of global diplomacy could have been circumvented by using more nukes.
There are people around here who are experts on nuclear and diplomatic history who can give detailed answers to this - eg. about the fact that at the end of WW2, the US didn't have more nukes. I just want to talk about some of the ethical and political basics.
What do we mean when we talk about "nuking" a country. Generally we're talking about the destruction of cities, the mass killing of hundreds or millions of people, injuries to many more. Imagine if you marched a division into a city and started shooting every man, woman and child they saw and blowing up every building they could. The results might be comparable.
The nuclear weapons used on Japan were justified on the grounds that to defeat Japan a ground invasion would be necessary, and this could cost hundreds of thousands of lives. The bombs were dropped to force Japanese unconditional surrender.
If the US were to attack the USSR with nuclear weapons, what would the objectives be? What would you achieve by destroying Vladivostok, St Petersburg, Moscow, etc. and killing their populations? Are you attempting to change the government by force? To cause so much destruction that the country is unable to threaten any others? You're setting starting a new war, and the killing of millions, off against some possible future gains.
You say:
a lot of global diplomacy could have been circumvented by using more nukes.
Let's put those two things against one another - and this assumes you actually achieve your objective (which I don't think would be the case). One the one hand: a lot of global diplomacy. On the other: the killing of millions of people. Which sounds like the better option?