"Nuclear-weapon states should negotiate and conclude a treaty on no-first-use of nuclear weapons against each other or make a political statement in this regard," Sun said.
China and India are currently the only two nuclear powers to formally maintain a no first use policy. Russia and the United States have the world's biggest nuclear arsenals.
I think you overestimate how many nukes it would take to cause the end of the world. Unless you mean "every piece of land is a radioactive wasteland" end of the world.
If just India and Pakistan were to go to nuclear war with each other, in their small localized region of the world, 27 million people would die from the carnage. The resulting nuclear Autumn would be enough to change agriculture and starve 250 million people worldwide.
I'm all for countries vowing not to use nuclear weapons first, but what is the point of a treaty? If a country does use nuclear weapons first, I think other countries are going to be less concerned about breaking the treaty and more concerned about WW3 and Armageddon.
And given that both the US and Russia have shown scant regard for treaties in recent years with major changes to policy, surely the treaty wouldn't be worth the paper it's printed on.
If a country does use nuclear weapons first, the other countries aren't going to be concerned with the treaty at all because the first country already broke it.
It takes a lot of people to launch a nuke. While missile operators are trained to act quickly, they are also drilled hard on adherence to policy. A 94% on the test for that policy is a failing grade.
And while I think you're very right to not trust the US or Russia to adhere to treaties, if said treaty requires that training policies and doctrine reflect the no first strike stance, that would mean a whole lot of people would have to be willing to violate that treaty in order to launch first. Heck, there's been incidents during the Cold War where a single person's hesitancy to follow approved launch policy has averted total nuclear war.
I think a treaty and accompanying training and doctrine could create sufficient barriers to make a nuclear first strike far less likely, though, of course, not impossible. But that alone seems like a worthwhile thing to pursue.
Last I remember, USA was the only country to have abused nukes against Japan, and later USA and UK sent nuclear ships to nuke India (Russia helped save us from those white devils). USA also supplied banned clusterbombs to NATO proxy Ukraine, which they used against Russia. Russia neither used nukes nor banned weapons.
While I don't think it bears much on how reasonable it is to suggest nuclear powers agree to never strike first, China's arsenal is uniquely well designed for this kind of strategy. They employ zero static sites, unlike the US and Russia, relying on mobile launchers, subs and bombers. This makes them tactically poised for a retaliatory strike as they don't have as much of the risk of losing their launch sites in a first strike. The US doctrine of preliminary strike in the event a nuclear attack seems likely is designed to protect their ability to launch at all.
While this kind of treaty would be slightly "advantageous" to China, it's only because they set up their nuclear arsenal with this far more reasonable and less aggressive strategy in mind from the get go while Russia and the US would have to adapt and convert their arsenal.
Russia also maintains a no first strike policy, unless that changed since I last got stuck in a rabbit hole about nuclear policy. The US is the only major country in the world to maintain a first strike policy with nuclear weapons that I know of.
Folks, very smart people are saying it. I talk to CEOs, generals, every day they tell me. They tell me China is a problem, they say "we've got a problem with China. We've gotta do something about China." Everybody's saying it. That's what they tell me.
This is directed to the US, UK, France, and Pakistan.
China and india already have no-first-use policies. Russia inherited one from the USSR, which was dissolved when the west coup'd them and immiserated their people. Russia's lack of a no-first-use policy is directed at the guys who represent an existential threat to them.
"Russia makes constant nuclear threats and doesn't have a no first use policy, but it's totally entirely the fault and moral obligation of the us. Totes definitely."
China and India are the only responsible players on the world stage and it shows.
Cojncidentally, they're also the two nuclear-armed countries who have been involved in the fewest conflicts, and who's conflicts have been resolved the most quickly.