If you’re interested in this topic, read “The Real North Korea: Life and Politics in the Failed Stalinist Utopia” by Andrei Lankov.
I think you are right that there is a "prestige" factor to this as well. China doesn't want to lose an ally, regardless of whether having that ally benefits them much, because they would look weak backing down to the US.
Its same as saying that there is no difference if Cuba will be "east" aligned and have USSR army/nukes or Mexico - after all, it is easy enough to launch nukes from both places.
You think from a "nuke" perspective. There are much more perspectives, like controlling water borders, locking important Chinese ports etc.
It's about preventing the unification of Korea and allowing the US military to get closer to China's territory. That's a double loss as far as China is concerned strategically.
The situation has an easy solution. China collapses North Korea as it exists today and pays off all the military leadership (which actually runs the country); said military cabal gets to live in China, and doesn't get prosecuted for war crimes (all obvious requirements from their perspective). The US, South Korea and China put together an initial trillion dollar, 20 year, package for economic recovery. The US & South Korea agree to cede between 1/3 and 1/2 of North Korea to China, to be used as a form of territory buffer between the US / S.Korea and China. The US agrees not to position its troops any closer to Chinese territory (ie not to occupy any of the territory South Korea acquires), various rules could be put into place that everyone agrees upon to ease China's concerns.
This is a trivial problem to solve as far as the big problems of the past century go.
What's not trivial, is that North Korea's nuclear & missile technology is going to keep pushing forward, which will eventually spur the US / Russia / China to begin aggressively pushing their nuclear technology forward again. Further, North Korea will attempt to hand their nuclear technology to other nations, as there are no real consequences for them doing so (oh no, more sanctions), only the benefit of spreading nukes around further which lessens the spotlight on them.
North Korea isn't interested in proliferation. They want (and have) nukes to keep the United States at bay. Historically, the US has no problem attacking states without nuclear weapons but never does so to states with them. It's a good strategy.
Of course they're extremely interested in proliferation. Just as Pakistan, China, India, France, Israel, Britain and Russia were all interested in proliferation (insofar as it suited their interests) and for exactly the same reason. The only reason the USSR and China got nukes in the first place, is they had a desperate self-interest in proliferation. North Korea's acquisition of nuclear weapons was also proliferation, which they were extremely interested in.
North Korea would love nothing more than to give the US & Co. other nuclear problems to deal with. The more so called rogue nations (or really anybody would do) with nuclear weapons there are, the easier it is for North Korea to justify keeping theirs, the less unique the North Korea situation becomes, the less pressure there will be on North Korea to give their weapons up. If five new nations pop up with nuclear weapons, the premise of North Korea being a rogue nuclear entity loses most of its punch, and the sanctions would wilt accordingly.
I might be wrong however. China is very greedy when it comes to territories it has historically regarded as tributaries, and Korea has been one for thousands of years. Maybe they would use that excuse for an outright invasion, like they did in Tibet?
China collapses the DPRK and allows it to be reunified under South Korean leadership. The US withdraws all armed forces from South Korea. Both China and the US agree that Korean territority is inviolable. With nuclear consequences if either / anyone violates this.
North Korea avoids its leadership being killed in a war / assassination.
China avoids the US on their borders.
The US disarms the North Korean threat.
(South) Korea gains an incredible security guarantee and becomes a unique crossroads for the region.
Win/win/win/win.
Much like China has very specific requirements/wants out of the situation (they'd want the US gone from Korea), it's very unlikely the US will want to cede that strategic position. Both sides are playing that angle and have been for decades, which is obviously making the situation more difficult to resolve.
I suspect the US would be the biggest problem in the full removal scenario, the military industrial complex wouldn't want to give up that beachhead. China would be the biggest problem in the mixed compromise scenario (they'd have very rigid demands that wouldn't be easy for the US military & political machine to swallow).
If you think this is an "easy solution", you clearly haven't talked to Koreans much. You might as well cede Alaska to Russians.
(Those armchair diplomats...)
Right now China/Russia are in a position where they have very little to lose and can just sit back and watch the US embarrass itself. They can't be seen as enabling NK, but beyond that they win by default in that we are distracted by it and look weak.
Russia has very little to gain or lose in this whole situation, but they benefit so long as it isn't resolved. As long as Russia holds a veto in the security council, nobody will be trying to take action on Ukraine, since they can start vetoing NK sanctions to make a point. Maybe more importantly, while the US tries to build an alliance to invade NK (possibly inevitable), Russia can sit back and call for calm and peace and de-escalation. This doesn't undo their Ukraine grab, but it creates an equivalency between Russian and US policy.
If I were China I would wait until I could horse trade. They want mineral rights in the south china sea, and Japan/SK/US (who are the primary states who can resist their island grabs) want to regime change NK. I predict they will do the minimum required by the UN and passively resist any other attempts to defuse the situation (in fact I think the more they pressure NK the more they make war inevitable. NK is now going to start starving and it's leadership may have to become hyper-aggressive) until they are paid out. Even then they will insist on concessions such as 'no US troops in the former NK'. If I were China I would participate in korean unification, but only with the condition that the US pull 100% of all military assets from the unified korea (since what can the US claim is the reason to keep them there if NK doesn't exist?), and that the US/SK/Japan concede that china owns the claimed undersea minerals.
Now is the "election season" in the middle kingdom.
Also there aren’t really ‘ethnic North Koreans’, just ethnic Koreans. The border doesn’t affect the ethnicity in that way, because if anyone from North or South Korea did an ancestry test it would just say ‘Korean’ or ‘Korean peninsula’.
If shit went down with DPRK and the US, wouldn't china aggressively go after their other interests: Taiwan and Hong Kong with an iron fist, putting the US at a stalemate because now china controls 90% of the worlds information technology manufacturing capacity - this the US is fucked and would never start to attack troops in Taiwan and Hong Kong else literally kill the entire worlds non-Agra infra?
So, with the ineptitude of trump, if I were playing Risk, and I were China, I'd play that card immediately.
Just invade Taiwan and HK with massive troops, but do it as a peaceful occupation, and just take control of all banking and manufacture outbound and then the US would just have to say "darnit, what do you want" and the tides of the next century flip to China's favor.
Conspiracy theory time:
This is one of the reasons the US heavily funds MIC tech from Israel, the tech innovation coming from there with the subsidies and the closeness are massive - and they aren't china... so they have been focusing on exact and precise cyber weapons instead of massive production volume.
If the "weapon" is a small scale team of cyber warfare experts with incredible tools built with unlimited funding, and they don't even sit in Israel - then taking them out will be much harder.
As opposed to bombing a plastic widget factory in china...
Heck. - they are prolly on a secret USs Jimmy carter sister sub with undersea vampire taps already...
We have a strategic reserve of oil, I'm sure we have a strategic reserve of Silicon Valley components which were made in china to keep up various operations..
Your scenario is pretty absurd considering history. If it were necessary, the US could build a hundred plus factories in the next year to churn out whatever IT technology was needed for its domestic well-being (in an extreme scenario where it was literally cut off). The US has hundreds of leading tech companies with the specialized knowledge required to do so, and a long history of pulling off incredible feats of industry when pressed to do so. It has an existing massive manufacturing capacity (China only passed the US in manufacturing output in 2011-2012), that comes in all shapes and sizes. The US also has the banks, private capital, public capital markets, entrepreneurs, thousands of technology companies (including most of the largest tech companies on the planet), accumulated decades of IT knowledge among the laborforce, the universities (R&D, science capability, tech labs, whatever the US could possibly need), a huge tech labor pool, any commodities needed, and the global reserve currency - all of which would be put to use. The US can marshal its vast resources when required, it has proven that repeatedly.
I know that yours is likely the accepted scenario to the US government, but I look around at my economy in San Francisco - every single object within 5 miles of me has been at least partially made in China. With a very small exception to certain things.
Sure, we can locally source our artisan recovery with organic planks, but if you're expecting the US to instantly turn out massive scale of anything other than food, I dont think it will happen.
Now, thats not to say we dont have incredible allies who can produce a massive amount of components and materials needed - but Target and Walmart are going to be empty in weeks.
All laptops and cellphones stop flowing into the US. Server and networking components that arent made in china, but are required for final assembly are dead.
Christ, recall the Tsunami knocking out global hard-drive supplies?
Yeah, you're comment is just as absurdly inflated.
You're talking about a scenario that threatens the existence of the US, its economy and its people. It would be equivalent to WW2. The response would be predictable accordingly: massive industrial mobilization.
The US already has a long history of churning out things at massive scale, long before China got into that game. It was primarily the US that built up China's manufacturing capabilities from the beginning, providing both the know-how and the capital. It also wasn't that long ago, you're talking about only going back to the early 1990s (China's GDP was a mere $360 billion in 1990). Further, the US presently manufactures things at massive scale, its manufacturing output is larger than the next five biggest manufacturing economies combined. Your premise falls apart just on that fact alone.
Companies such as Dell, Apple, HP, Intel, Cisco, SanDisk, Seagate, IBM, and thousands more, have all manufactured IT technology in the US in the last 20, 30, 40 years. The notion that couldn't be restarted in a national emergency in which the survival of the US is threatened, is very far-fetched.
The US also has numerous other allies that could help, such as South Korea. They'd be more than happy to dramatically ramp up their output and expand if Taiwan were cut-off. Perhaps India would like to take part of Taiwan's business, the US could distribute capital investment to aid in that as well, just as it originally helped to build up Taiwan's IT manufacturing capabilities in the first place.