Is it your suggestion that nuclear weapons aren't any different from conventional weapons?
Weapons come in many varieties, none exactly alike and each with its optimal use cases. Only an idiot would suggest they do not differ from each other. "Conventional" is taxonomic, not empirical or practical.
My suggestion is that nuclear weapons too have legitimate use cases in a just war, and in some scenarios may indeed be the most responsible and humanitarian choice. We shouldn't take them off the table just because
it has the scary word "nuclear" in the name.
Ukraine is ruthlessly carpeting its eastern regions with fiber cables, land mines, and other hazards that will have environmental, health, and safety implications for decades to come. Ukraine is ruthlessly causing toxic waste spills and burns on an almost daily basis now, with massive unregulated greenhouse gas emissions resulting, along with - again - environmental, health, and safety implications for decades to come.
The coalition that liberated Kuwait used heavy earth-moving equipment to bury Saddam Hussein's troops alive under their own defensive works. Horrifying to think about, and probably some troops came home psychologically scarred from the realization of what they did. But a lot more of them came home alive than would have, if they had been thrown as a forlorn hope at the enemy walls. Fighting a just war never means putting your own soldiers in harms' way for honor, when more effective means of winning are available.
So yes, it is my suggestion that the environmental, health, and safety concerns about a particular weapon should be carefully considered when selecting it for use. And I think that according to this rubric, and setting aside the knee-jerk reaction to the mention of "nukular" weapons, and the generational boogeyman of global thermonuclear war, nuclear weapons do have their place in the modern arsenal of responsible warfare. It's likely a very niche place, but even so.
Hiroshima and Nagasaki are both thriving metropoles today. Clearly the long-term environmental impact of limited use of nuclear weapons can be managed.
In the more immediate context, the chief concern with nuclear weapons is the same as their chief advantage: They are extremely powerful explosions. This makes them very attractive, from a humanitarian perspective. More results from fewer sorties means fewer of your own people in harm's way - always a good thing in war, as the Ukrainians have reminded us. Too, more results from fewer sorties means a shorter, faster path to victory. This saves many more lives in the long run, especially when you factor in all the resources that are still available for reconstruction, rather than having been wasted in an inefficient battle for survival.
But that same explosive power makes them less discriminate than lesser weapons. Early on, this meant that they could only be used as city-killers, civilization-enders. And that has biased the entire conversation ever since. But here's something interesting: The west - particularly the US - invested heavily in technologies that would both reduce the minimum effective yield (smaller warheads) while increasing accuracy. A precision strike by a small bunker-busting nuke is an entirely different proposition from a hail-mary airburst over a major city because that's as precise as you can get.
Russia claims credit for the largest nuke ever tested, the Tsar Bomba. But the Tsar Bomba is a joke. It was too heavy to transport in any of their strategic bombers. Its blast was too big for the plane that delivered it to escape its effects. It could not fit onto any practical ballistic missile. While the US was developing smaller, more accurate nukes, the USSR was admitting technolgical defeat and trying to spin it as industrial supremacy.
So I ask,
should there be a deterrent against using really big bombs? Yes.
Should there be a deterrent against causing long-term environmental, health, and safety problems, in the service of winning a war? Yes. I just don't see how nukes don't already fit into the deterrence framework we apply to every other weapon and strategem of war.
I am not in favor of indiscriminate mass destruction to win wars. But even the Geneva convention accepts collateral damage through overkill, if overkill is the only weapon the commander has available at the moment when the military result is in question.
Our ethical approach to warfare must have nuance, must be willing and able to solve the trolley problem in practice, otherwise we have to condemn the Zelensky regime as perhaps one of the worst environmental and climate criminal organizations since Enron went to Bhopal. And they haven't used even a single nuke so far.