This is a peak Chinese liberal thought experiment. The population of every other nuclear power (except maybe the soviet union before it collapsed) knows the importance of MAD and would unequivocally advocate for revenge. Westerners have been fantasizing about exterminating all none-white for centuries. American politicians quote the Turner Diaries when they think nobody will notice. In Oakland, a city with one of the highest Asian populations in America, they have a square called "Jack London Square" named after a man who wrote about how he wanted to use biological weapons to exterminate all Chinese and then hunt down all the survivors. They teach this man's writing in gradeschool. For every person protesting Israel in the west there are 2 more who derive genuine pleasure from the suffering of Palestinians. Where do you live? I'm genuinely curious how anyone can come up with a thought experiment this naive. Have you just like, never talked to a westerner outside of hexbear or something?

The doctrine of nuclear deterrence only works if there is a credible threat of a second strike. Once it has been established that nuclear victims will not retaliate, it is open season for atrocities beyond your comprehension.

The credible threat of a second strike prevents a first strike. In order to have a credible threat, you must be actually willing to go through with it.

The best way of making a credible threat is to make it so that you have no choice in the matter. Russia's Dead Hand system automates the second strike, removing all human agency. Computer systems do not think about philosophy before dropping the other shoe.

If America had launched a first strike against China that will wipe out 90% of its population, should China retaliate?

Yes, the destruction would lead to world socialism and eventually galactic communism /j

but honestly yes, if country tries to wipe another one with nuclear weapons then the country in question should retaliate, i dont think humanity would collectively learn from that mistake if the china doesnt strike back, the world saw the destruction 2 atomic bombs did and it didnt stop the developing and constructions of more bombs with even worse destructive ability, only way we learn is if we experience a nuclear war and if that means the extintion of Humanity then it was probably deserved for building such terrible weapons

if you don't enact MAD when it counts then we'll live in a hellscape with open nuclear attacks going unchallenged. The 10% of people who survive got to remember the lesson or it will happen again and again.

Also, yes they should do it because fuck Amerikkka they can't keep getting away with it.

If 90% of China was killed in nuclear war the USA would not let the remaining 10% survive. They would hunt the rest of them down with drones or sanction/blockade them to death. At that point it is more important to return fire with every thing they have because the only way for the Chinese people to not be exterminated is if USA is in as bad or worse a situation.

Yes. MAD is why governments exert extreme controls on their own nuclear protocols and the whole point of MAD is that China, Russia and the US would retaliate and kill the entire population of the aggressive nuclear power. Of course China 'should' retaliate, because that is what prevents the scenario from happening in the first place.

What is irrational is the french nuclear doctrine of 'if you sink one of our ships, we'll nuke you'.

Yes. In order for MAD to work, there has to be a credible threat of retaliation. By not having a second strike policy, you allow the first strike to happen.

It wouldn't matter. There is no way to replace the global industrial output of China on the world stage if the labor force from which that industrial output is derived is knocked out. The globe would immediately spiral into a recession the likes of which no one has ever seen, particularly with the vaporization of most of the world's smart phone manufacturing infrastructure, battery infrastructure, and components infrastructure.

They would be ethically obliged to retaliate, but the world would be essentially fucked for the next three to four decades regardless of any other actions.

The question is only really a philosophical problem if you're assuming that China and the US are the only two nations on the planet. Given that other nations, especially nuclear nations, exist, then I think a second strike against America (and perhaps the UK and France and other Western nuclear nations, but not necessarily as they don't have the ability to dominate the world in nearly the same way that America could hypothetically do if America had a competent imperialist strategy unlike today) is the only correct choice. America and China are irradiated hellholes and billions have or will die, but it's a world with one less hegemonic imperialist power, and that's a world that does still have a potentially communist future.

Someone other than me would have to make the call about whether preventing a global fascist future (that might even go spacefaring and propagate colonialism and imperialism throughout the galaxy and universe) is worth the death of absurd numbers of people - all I can do is say that this is the decision Stalin made, and I regard him as a pretty smart and competent person.

just aim all of your nukes at washington or wherever else the ghouls keep their doomsday bunkers. you have to retaliate in some manner or america will just successfully take the entire planet as its nuclear hostage. imagine the belgian congo but across the whole planet for at least a few decades if not centuries or millenia, and assisted by modern military and surveillance technology, and with no hope of resistance due to the nuclear trump card. don't give america all your money? get nuked. give in to their demands? now they can afford more cops to brutalize you and more drones and etc. to watch and control you. The question then boils down to whether you think extinction/death is better than eternal fascism. once a hypothetical competent america achieves nuclear-based economic, political, and military dominance, there will be nothing stopping them from enforcing racist eugenics programs at best and genetic engineering at worst to design their own twisted caste system, doing their best to manufacture the perfect workers and consumers, the most obedient population possible. think something along the lines of reproductively sterilized, disposeable workers with cranial bomb and tracking devices installed at birth to ensure compliance with any orders. america would also have a monopoly on the resources to attempt space travel. if this is successful, this fascist techno-dystopian america will be the only 'humanity' that spreads to the stars, any non-edited humans being genocided into extinction by this point, not hard given total global military dominance and air superiority and manufacturing control enabled by this hypothetical nuclear houdini america's inevitable extortion of every other country's resources and wealth.

Hot take: revenge is not an entirely useless thing. It shows everyone you have the capability to retaliate when you are wronged. If you don't do revenge some will think they can wrong you as much as they want which might create future situations of you being wronged again. And on the wrongdoer side, you cripple their ability to do same again or punish them so they don't it again. Send nukes so that remaining people can live

The only lesson that people in the West would learn is this:

No, because the amount of nuclear firepower needed to kill 90% of China's population would be enough to generate firestorms that would doom humanity to mass starvation.

China should not give the Americans the mercy of a quick nuclear death.

If America had launched a first strike against China that will wipe out 90% of its population, should China retaliate?

It's not a case of "should". The PRC will retaliate with nuclear force should any country armed with nuclear weapons do the unthinkable against the PRC.

This is the PRC's nuclear deterrence policy.

Communists must not be pacifists because mercy does not exist for us. Peace and prosperity is our desire and the world's desire, and any attempt to spoil it must be crushed ruthlessly.

Before nuclear Holocaust is unleashed it is necessary for their deterrence to work, and arguably the only moral choice, to have no disambiguity whatsoever. Everybody needs to be painfully aware that you will retaliate in full force in the case of a nuclear attack. You preferably need something like the Russian Dead Hand system, ensuring that you will retaliate even from beyond the grave.

If the Americans gets just a tiny hope that they can do a nuclear attack without being destroyed themselves the risk of them doing so increases dramatically.

But that everything changes once the first volley of nukes are flying. At that point your deterrence obviously didn't work and you're toast no matter what. Humanity as a whole is going to have an extremely hard time as a result of the American attack. Retaliating at this point would only serve as vengeance and add untold misery on top of the already unfolding cataclysm. The moral case for pushing the button at that time is much weaker. Personally I come out in favour of not doing it.

So in essence, the best position is the impossible position of fully believing in and preparing for retaliation but not actually doing it if push comes to shove.

The world is is kind of fucked either way. If MAD has broken down and the nukes are actually flying the entire planet will be destabilized as various environmental systems break down. More nukes don't help and I can't in good conscience say that I should make the decision or know what would be best for humanities future. The capitalist empire can't really sustain itself either way if nuclear hellfire has scarred and destroyed the world. There would only be global hatred for the Americans if they nuke the chinese like that.

I can understand both decisions from the Chinese though. It would only be fair, after all, for the chinese to retaliate.

Here's a tweak: based on what we know about America's antique nuclear ICBMs, if America attempted to launch a first strike and a significant portion of the launches failed in mid-air and the majority of the rest were intercepted by China's defenses (I assume they're working on if not already have hypersonic interceptor missiles), should China retaliate?

I would say the answer to both your and my hypothetical situation is yes.