I don't think either sides would be interested in a second Cold war.
But if a major conflict appears in the future, sure as hell I think most governments with nuclear weapons would be ready to pull them off (including the US). Otherwise there wouldn't be any nukes anymore. It's a disaster really since the major problem with nuclear weaponry is that it effects more than just
one battle in
one war. I read an article in Scientific American (I think it was) about today's nuclear weapons.
One bomb is enough to make New York a ghost town, which I guess everyone already knew, but it's still a horrible fact.
Now I'm going to say something that might upset people though so read this with care and don't misinterpret what I'm trying to say.
I think that in a way, Hitler being a blind, stupid anti-Semite was actually a fortunate (excuse me for using this word but my vocabulary couldn't find anything more appropriate) thing. If he would've embraced the skills of the German-Jewish scientists the Third Reich would probably have been the first to develop nuclear warheads. And if that would've happened a lot more people would've died and Europe would be a disaster still.
Also, the US dropping the infamous Nagasaki/Hiroshima bombs was also, in a way, a fortunate thing in historical perspective. If the world wouldn't have realized the true ferocity of nuclear weapons (which Einstein warned about) that day, we would very likely had been victims to an H-bomb in later years. And the biggest H-bomb dropped (yet), the Tsar Bomba of the Soviet Union (detonated 1961), had a blast radius... well I won't bother explaining further, just take a look at this picture:
It's painful to say, but in some way the most horrible events of history took a bullet for possible, worse outcomes. I'm not in any way saying we should be glad that the Holocaust happened, but that from a historical perspective it might have prevented other disasters. History is just a big line of chance.