Oh, I see- you envision a ' limited nuclear catastrophe '. Good luck with that. People of like mind should be removed from positions of power immediately.
The main purpose of nuclear weapons seems to be to scare opponents away from fighting a war, not to do much in the war that follows. That being said, there is a flaw in nuclear weapons that would allow for a victory.
First, you cannot scare opponents away from a war that you start. So Ukraine could care less that the Russians who invade them have nuclear weapons, and the South Koreans would not care that the North Koreans have nuclear weapons if the North Koreans invaded. Second, it becomes extremely destructive to everyone if the nuclear weapons are used. There is a real chance Russian or North Korean military commanders would refuse an order to use them. When you game it all out, nuclear weapons can sometimes lead to a complete defeat that the lack of nuclear weapons would have avoided.
There is also a less understood chance that South Korea and the USA would be more aggressive if they thought they had to go to war with North Korea. There are plans to try to take out the nuclear weapons and/or the command structure in North Korea, when there was no similar plans for Iraq. This could mean defeating North Korea would go faster than defeating Iraq.
The strategy is quite simple, based upon known values. The US used atomic bombs , quite unnecessarily, against a defeated opponent. It was a callous slaughter of hundreds of thousands of civilians, men, women and children. So no country can expect anything different from the US. Their only hope of survival, as a free society of their own choosing, is to also be nuclear armed. Nothing else will turn the insane point of US power-craving- as we've seen in the Middle East and Afghanistan. The US even backs fascist Israel militarily and goes to war on its behalf, even though the UN- and the world at large- marks it as a criminal state.
India, Pakistan and N. Korea are nuclear armed- and no friends of the US empire. It goes without saying that neither the Russian nor the Chinese are particular about which other, non-Western, countries develop nukes for their own defense against US ' democracy '. So the US, by its nuclear madness, set in motion a nuclear chain of events that it cannot control. It hopes to continue its hegemony through conventional warfare- but the world has had enough of that. It's likely that the Russians would come to the aid of Iran , once the US attacks it, as planned- and the Chinese will not permit the defeat of N.Korea. So, best that Yangui goes home, Walt- and then you can quit trying to formulate how America is going to continue into the future by means of conventional warfare overseas. Imo- it ain't gonna happen